Long-term leisure time physical activity and properties of bone: A twin study

Effects of physical activity on bone properties, when controlled for genetic effects, are not fully understood. We aimed to study the association between long-term leisure time physical activity (LTPA) and bone properties using twin pairs known to be discordant for leisure time physical activity for at least 30 yr. Volumetric BMD and geometric properties were measured at the tibia shaft and distal end using pQCT in 16 middle-aged (50-74 yr) same-sex twin pairs (seven monozygotic [MZ] and nine dizygotic [DZ] pairs) selected from a population-based cohort. Paired differences between active and inactive co-twins were studied. Active members of MZ twin pairs had larger cortical bone cross-secti…

Muscle strength in male athletes aged 70-81 years and a population sample.

Muscle strength characteristics of different muscle groups were studied in active male strength-trained (ST, n = 14), speed-trained (SP, n = 16), and endurance-trained (EN, n = 67) athletes aged between 70 and 81 years. A population sample of similar age (n = 42) served as a control group. The isometric forces for hand grip, arm flexion, knee extension, trunk extension, and trunk flexion were higher for the athletes than the controls and higher for the ST than EN group. The SP athletes showed higher values in knee extension and trunk flexion than the EN group. When the isometric muscle forces were related to lean body mass, significant differences still existed between the athletes and cont…

Knee extension strength and walking speed in relation to quadriceps muscle composition and training in elderly women.

Summary. Knee extension strength, walking speed, quadriceps muscle mass and composition of the muscle compartment were studied in 66 to 85-year-old female athletes and controls. Maximal voluntary knee extension force, force/body mass, extension torque, torque/body mass and walking speed were higher for the athletes than the controls. A muscle index indicating intramuscular fat and connective tissue measured using ultrasonography was lower for the athletes than the controls. There were no differences between the study groups in knee extension force related either to cross-sectional area (CSA) or lean tissue area (CSAL) of the quadriceps. Within the subgroups, there was no significant correla…

Muscle cross-sectional area and structural bone strength share genetic and environmental effects in older women

The purpose of this study was to estimate to what extent muscle cross-sectional area of the lower leg (mCSA) and tibial structural strength are influenced by common and trait-specific genetic and environmental factors. pQCT scans were obtained from both members of 102 monozygotic (MZ) and 113 dizygotic (DZ) 63- to 76-yr-old female twin pairs to estimate the mCSA of the lower leg, structural bending strength of the tibial shaft (BSIbend), and compressive strength of the distal tibia (BSIcomp). Quantitative genetic models were used to decompose the phenotypic variances into common and trait-specific additive genetic (A), shared environmental (C), and individual environmental (E) effects. The …

Regular Strength and Sprint Training Counteracts Bone Aging: a 10- year Follow-up in Male Masters Athletes

According to cross-sectional and interventional studies, high-intensity strength and impact-type training provide a powerful osteogenic stimulus even in old age. Longitudinal evidence on the ability of high-intensity training to attenuate age-related bone deterioration is currently lacking, however. This follow-up study assessed the role of continued strength and sprint training on bone aging in 40- to 85-year-old male sprinters (n=69) with long-term training background. pQCT-derived bone structural, strength and densitometric parameters of the distal tibia (5% distal-proximal tibia length) and tibial midshaft (50% length) were assessed at baseline and after 10 years. The groups of well-tra…

Absence of an aging-related increase in fiber type grouping in athletes and non-athletes

The ageing-related loss of muscle mass is thought to be partly attributable to motor neuron loss and motor unit remodelling that result in fibre type grouping. We examined fibre type grouping in 19- to 85-year-old athletes and non-athletes and evaluated to which extent any observed grouping is explained by the fibre type composition of the muscle. Since regular physical activity may stimulate reinnervation, we hypothesised that fibre groups are larger in master athletes than in age-matched non-athletes. Fibre type grouping was assessed in m. vastus lateralis biopsies from 22 young (19-27 years) and 35 healthy older (66-82 years) non-athletes, and 14 young (20-29 years), 51 middle-aged (38%6…

Effects of strength and endurance training on thigh and leg muscle mass and composition in elderly women

The effects of 18 wk of intensive strength and endurance training on knee extensor, knee flexor, and lower leg muscle mass and composition were studied in 76- to 78-yr-old women. Muscle cross-sectional area (CSA), lean tissue CSA, and relative proportion of fat were determined using computed tomography. The strength-trained women increased their total muscle lean tissue CSA of the thigh (1.5%; P = 0.035), quadriceps CSA (4.5%; P = 0.021), quadriceps lean tissue CSA (5.8%, P = 0.009), and mean Hounsfield unit of the lower leg muscles (11.2%; P = 0.035) compared with the changes that occurred in the control group during the experiment. The change in quadriceps lean tissue CSA because of the …

Bone density of the calcaneus and fractures in 75- and 80-year-old men and women

Bone mineral density of the calcaneus in relation to fractures was studied both retrospectively and prospectively among the 75- and 80-year-old men and women resident in the city of Jyväskylä, Finland, in 1989 and 1990, respectively. The bone measurements were performed at the calcaneus by 125I-photon absorption. Retrospective fracture (RF) history after age 50 was collected by questionnaire and interview, and reported fractures were checked from medical records. In the retrospective study, in the 75-year-olds a fracture was found in 22% (n = 22) of men and in 45% (n = 84) of women. The corresponding figures for the 80-year-olds were 16% (n = 9) and 35% (n = 48). Over half of the fractures …

Growth patterns at distal radius and tibial shaft in pubertal girls: a 2-year longitudinal study.

Bone changes, in terms of both size and BMD, were assessed longitudinally in pubertal girls. Before puberty, BMD at the distal radius declined, whereas bone size increased, suggesting that normal growing girls experience a transient period of increased bone fragility. This could explain the elevated low-trauma forearm fracture rates reported in earlier studies. Introduction: Longitudinal data on bone growth during puberty are sparse. Such information is needed to understand the sequence of biological changes, the physical and mechanical consequences for the growing skeleton, and the implications for later life. Materials and Methods: The geometric properties and volumetric BMD (vBMD) of the…

Vitamin D status as a determinant of peak bone mass in young Finnish men.

Severe vitamin D deficiency causes rickets, but scarce data are available about the extent to which vitamin D status determines the development of the peak bone mass in young adults. Our aim was to evaluate the prevalence of vitamin D deficiency [serum 25-hydroxyvitamin D (25-OHD) less than the lower limit of the reference range of 20–105 nmol/liter] and the relationship between vitamin D status and peak bone mass among young Finnish men. A cross-sectional study of determinants of peak bone mass with data on lifestyle factors collected retrospectively was performed in 220 young men, aged 18.3–20.6 yr. One hundred and seventy men were recruits of the Finnish Army, and 50 were men of similar …

Estimation of structural and geometrical properties of cortical bone by computerized tomography in 78-year-old women

The structural and geometrical properties of the tibia shaft were investigated at two sections by means of computerized tomography (CT) in 78-year-old women with high (n = 19) and low (n = 17) calcaneal bone mineral density (BMD, g/cm3) previously measured by 125I-photon absorption. The high BMD group had a 20-21% higher tibial BMD and 9-12% higher bone cross-sectional area than was observed in the low BMD group. The distribution of bone mass indicated that the low BMD group had lost bone mainly from the endosteal surface, especially in the anterior part of the tibia. However, both groups had a similar basic pattern of mass distribution at the measured sections. The high BMD group had highe…

Estrogen receptor alpha polymorphism modifies the association between childhood exercise and bone mass: follow-up study.

This follow-up study confirms our previous findings that the ER-α PvuII polymorphism (Pp) modulates the association between exercise and bone mass. The differences in bone properties of girls with consistently low physical activity (LLPA) and consistently high physical activity (HHPA) were evident only in those bearing the heterozygote ER-α genotype (Pp). In particular, areal bone mineral density of the total femur, bone mineral content and areal bone mineral density of the femoral neck, and bone mineral content and cortical thickness of the tibia shaft were significantly (p < .05) lower in the Pp girls with LLPA than in their HHPA counterparts. These findings might partly explain the ge…

Walking and Running Require Greater Effort from the Ankle than the Knee Extensor Muscles.

The knee and ankle extensors as human primary antigravity muscle groups are of utmost importance in a wide range of locomotor activities. Yet, we know surprisingly little about how these muscle groups work, and specifically, how close to their maximal capacities they function across different modes and intensity of locomotion. Therefore, to advance our understanding of locomotor constraints, we determined and compared relative operating efforts of the knee and ankle extensors during walking, running, and sprinting.Using an inverse dynamics biomechanical analysis, the muscle forces of the knee and ankle extensors during walking (1.6 m·s), running (4.1 m·s), and sprinting (9.3 m·s) were quant…

Retinal light sensitivity of the central visual field among 70- to 81-year-old men and women.

Retinal light sensitivity of the central visual field (0-30 degrees), visual acuity, intraocular pressure and pupillary size were screened in 42 men and 42 women aged 70 to 81 years. The subjects were randomly selected from the population register. After excluding the diagnosed glaucoma cases, the men had better visual field light sensitivity values than the women. They also had lower intraocular pressure and a wider pupillary diameter than the women, whereas there were no differences in visual acuity between the sexes. When the effect of pupillary size was controlled the differences in visual field light sensitivity values between men and women became non-significant. Among these elderly p…

Sport Performance in Master Athletes: Age‐Associated Changes and Underlying Neuromuscular Factors

Calcaneal Bone Mineral Density Predicts Fracture Occurrence: A Five-Year Follow-up Study in Elderly People

A 5-year follow-up study investigated calcaneal bone mineral density (BMD) and changes in BMD in relation to fracture occurrence. The subjects comprised two cohorts born in 1914 and 1910 living in the city of Jyväskylä in central Finland. One hundred and three men (82%) and 188 women (73%), aged 75, and 57 men (74%) and 136 women (65%), aged 80, of the eligible population participated in the baseline bone measurements. The follow-up bone measurements were obtained for 59 men (68%) and 119 women (66%), aged 80 years, and for 21 men (53%) and 61 women (48%), aged 85 years. During the follow-up period, 8 men and 36 women from the younger and 11 men and 24 women from the older cohort sustained …

Greater maintenance of bone mineral content in male than female athletes and in sprinting and jumping than endurance athletes: a longitudinal study of bone strength in elite masters athletes

Abstract Summary We investigated longitudinal changes in tibia bone strength in master power (jumping and sprinting) and endurance (distance) athletes of both sexes. Bone mass but not cross-sectional moment of inertia was better maintained in power than endurance athletes over time, particularly in men and independent of changes in performance. Objective Assessment of effects of sex and athletic discipline (lower limb power events, e.g. sprint running and jumping versus endurance running events) on longitudinal changes in bone strength in masters athletes. Methods We examined tibia and fibula bone properties at distal (4% distal-proximal tibia length) and proximal (66% length) sites using p…

Assessing body composition with DXA and bioimpedance: effects of obesity, physical activity, and age.

Objective: This study evaluated to what extent dual-energy X-ray absorptiometry (DXA) and two types of bioimpedance analysis (BIA) yield similar results for body fat mass (FM) in men and women with different levels of obesity and physical activity (PA). Methods and Procedures: The study population consisted of 37–81-year-old Finnish people (82 men and 86 women). FM% was estimated using DXA (GE Lunar Prodigy) and two BIA devices (InBody (720) and Tanita BC 418 MA). Subjects were divided into normal, overweight, and obese groups on the basis of clinical cutoff points of BMI, and into low PA (LPA) and high PA (HPA) groups. Agreement between the devices was calculated by using the Bland–Altman …

OGT and OGA expression in postmenopausal skeletal muscle associates with hormone replacement therapy and muscle cross-sectional area

Protein glycosylation via O-linked N-acetylglucosaminylation (O-GlcNAcylation) is an important post-translational regulatory mechanism mediated by O-GlcNAc transferase (OGT) and responsive to nutrients and stress. OGT attaches an O-GlcNAc moiety to proteins, while O-GlcNAcase (OGA) catalyzes O-GlcNAc removal. In skeletal muscle of experimental animals, prolonged increase in O-GlcNAcylation associates with age and muscle atrophy. Here we examined the effects of hormone replacement therapy (HRT) and power training (PT) on muscle OGT and OGA gene expression in postmenopausal women generally prone to age-related muscle weakness. In addition, the associations of OGT and OGA gene expressions with…

DIFFERENTIAL INFLUENCE OF PERIPHERAL AND SYSTEMIC SEX STEROIDS ON SKELETAL MUSCLE QUALITY IN PRE- AND POSTMENOPAUSAL WOMEN.

Aging is associated with gradual decline of skeletal muscle strength and mass often leading to diminished muscle quality. This phenomenon is known as sarcopenia and affects about 30% of the over 60-year-old population. Androgens act as anabolic agents regulating muscle mass and improving muscle performance. The role of female sex steroids as well as the ability of skeletal muscle tissue to locally produce sex steroids has been less extensively studied. We show that despite the extensive systemic deficit of sex steroid hormones in postmenopausal compared to premenopausal women, the hormone content of skeletal muscle does not follow the same trend. In contrast to the systemic levels, muscle t…

Serum osteocalcin in relation to calcaneal bone mineral density in elderly men and women: a 5-year follow-up

A 5-year follow-up study investigated serum concentrations of total (tOC) and intact (iOC) osteocalcin in relation to calcaneal bone mineral density (BMD). The study comprised two cohorts, 75- and 80-year-olds, both resident in the city of Jyvaskyla, Finland. Baseline OC and BMD were obtained for 161 men and 233 women, of whom 83 men and 189 women participated in follow-up bone measurements. The mean concentration of tOC increased from 9.6 +/- 4.3 to 13.2 +/- 8.5 microg/l (P = 0.001) in men and from 11.2 +/- 4.9 to 14.0 +/- 6.1 microg/l (P < 0.001) in women, whereas mean iOC decreased from 6.4 +/- 3.0 to 5.9 +/- 3.0 microg/l (P = 0.273) and from 7.7 +/- 3.7 to 6.9 +/- 3.4 microg/l (P = 0.02…

Effects of diet-induced obesity and voluntary wheel running on the axial and peripheral skeleton microstructure in mice

Effects of aging and life-long physical training on collagen in slow and fast skeletal muscle in rats. A morphometric and immuno-histochemical study.

Intramuscular collagen in a slow (m. soleus) and a fast (m. rectus femoris) skeletal muscle was studied by biochemical, morphometric, and immunohistochemical methods. Wistar white rats of 1, 4, 10, and 24 months were used as experimental animals. Our aim was to evaluate the effects of life-long physical training (treadmill running, 5 days a week for 1, 3, 9, and 23 months depending on the age attained). The biochemical concentration of collagen was higher in m. soleus than in m. rectus femoris and it increased in youth and in old age in m. soleus. The trained rats had higher concentrations of collagen than the untrained rats at 10 and 24 months. The morphometrically measured area-fractions …

Sprint and Strength Training Modulates Autophagy and Proteostasis in Aging Sprinters

Purpose Exercise and aging may modulate muscle protein homeostasis and autophagy, but few studies examine highly-trained middle-aged or older individuals. This study elucidated the effects of a new long-term training stimulus on markers of muscle autophagy and unfolded protein response (UPR) and on sprint running performance in masters sprinters. Methods Thirty-two male competitive sprinters (aged 40–76 years) were randomly divided into experimental (EX) and control (CTRL) groups. The EX training program was a combination of heavy and explosive strength and sprint exercises aimed at improving sprint performance. Fifteen and thirteen participants completed the 20-week intervention period in …

Quantitative ultrasonography of muscle: Detection of adaptations to training in elderly women

Abstract Objective: To develop quantitative ultrasonography in studying the adaptation of quadriceps muscle mass and composition to short-term physical training and rehabilitation in elderly women. Design: Randomized control trial. Setting: Measurements in a research laboratory and training in a fitness center and sports hall. Participants: Forty-two women, aged 76 to 78 years, with no indications against intensive physical exercise, randomly assigned to strength ( n = 16), endurance ( n = 15), and control ( n = 11) groups. Twelve subjects from the strength, 12 from the endurance, and 11 from the control group completed the study. Intervention: Supervised physical training 3 times a week fo…

Dietary acid load and renal function have varying effects on blood acid-base status and exercise performance across age and sex

Diet composition influences acid-base status of the body. This may become more relevant as renal functional capacity declines with aging. We examined the effects of low (LD) versus high dietary acid load (HD) on blood acid-base status and exercise performance. Participants included 22 adolescents, 33 young adults (YA), and 33 elderly (EL), who followed a 7-day LD and HD in a randomized order. At the end of both diet periods the subjects performed a cycle ergometer test (3 × 10 min at 35%, 55%, 75%, and (except EL) until exhaustion at 100% of maximal oxygen uptake). At the beginning of and after the diet periods, blood samples were collected at rest and after all workloads. Oxygen uptake, r…

Bone Density, Structure and Strength, and Their Determinants in Aging Sprint Athletes

This study was undertaken to examine bone properties in masters sprinters of different ages and younger reference subjects. In addition, the association of sport-specific ground reaction force, muscle, training, and hormone characteristics with the bone parameters was evaluated in the athletes.Bone densitometric, structural, and strength parameters were assessed by peripheral quantitative computed tomography at the distal and midtibia in 83 male sprinters (40-85 yr) and 19 physically active referents (31-45 yr). Between-group differences were analyzed by ANCOVA with body mass and height as covariates.Bone values were generally greater in athletes than referents, the greatest differences bei…

Muscular transcriptome in postmenopausal women with or without hormone replacement.

The loss of muscle mass and strength with aging is well characterized, but our knowledge of the molecular mechanisms underlying the development of sarcopenia remains incomplete. Although menopause is often accompanied with first signs of age-associated changes in muscle structure and function, the effects of hormone replacement therapy (HRT) or menopause-related decline in estrogen production in the muscles of postmenopausal women is not well understood. Furthermore the knowledge of the global transcriptional changes that take place in skeletal muscle in relation to estrogen status has thus far been completely lacking. We used a randomized double-blinded study design together with an explor…

Effects of 32-year leisure time physical activity discordance in twin pairs on health (TWINACTIVE study): aims, design and results for physical fitness.

AbstractThe physically active lifestyle is associated with low future morbidity and mortality, but the causality between physical activity and health is not always clear. As some inherited biological characteristics and childhood experiences may cause selection bias in observational studies, we sought to take them into account by identifying 16 twin pairs (7 MZ, 9 DZ, mean age 60 years) discordant for leisure time physical activity habits for thirty years. We conducted detailed health-related examinations among these twin pairs. Our main aims were to study the effects of physical activity and genes on fitness and body composition, with special reference to body fat compartments, metabolic s…

Motives for competitive sports participation in masters track and field athletes : Impact of sociodemographic factors and competitive background

Objectives Masters athletes due to their lifelong engagement in sport represent a unique group to study motivation for regular physical activity, but there is less scientific data on the sport motives in masters athletes. Therefore, the aim of this study was to evaluate the association of age, sex, education, nationality, competitive background and training amount with sport motives of masters track and field athletes. Methods 811 (254 women) athletes aged 35–89 years participated in European Veterans Athletics Championships in the year of 2000. Sport motives were assessed with a questionnaire and categorized into1) well-being, 2) competitive and performance 3) health and fitness motives. R…

Declining Physical Performance Associates with Serum FasL, miR-21, and miR-146a in Aging Sprinters.

Aging is associated with systemic inflammation and cellular apoptosis accelerating physiological dysfunctions. Whether physically active way of life affects these associations is unclear. This study measured the levels of serum inflammatory and apoptotic molecules, their change over 10 years, and their associations with physical performance in sprint-trained male athletes. HsCRP, cell counts, HGB, FasL, miR-21, and miR-146a were measured cross-sectionally (n=67, 18–90 yrs) and serum FasL, miR-21, and miR-146a and their aging-related associations with physical performance were assessed over a 10-year follow-up (n=49, 50–90 yrs). The cross-sectional study showed positive age correlations for …

Effects of age and life-time physical training on fibre composition of slow and fast skeletal muscle in rats.

The effects of age and endurance training on muscle fibre characteristics were studied in a slow (m. soleus, MS) and in a fast (m. rectus femoris, MRF) skeletal muscle. Wistar rats at ages of 1, 2, 4, 10, and 24 months were used as experimental animals. The trained rats were put to run on a motor-driven treadmill 5 d/wk beginning from the age of 1 month. The body weights of the animals increased continuously throughout their lives. The muscle weights increased up to the age of 10 months, after which they tended to decrease. The trained adult rats had lower body weights as well as lower muscle weights than the untrained adult rats. The amount of the intramuscular lipid decreased with age, es…

Muscle Cross-Sectional Area and Structural Bone Strength Share Genetic and Environmental Effects in Older Women

The purpose of this study was to estimate to what extent muscle cross-sectional area of the lower leg (mCSA) and tibial structural strength are influenced by common and trait-specific genetic and environmental factors. pQCT scans were obtained from both members of 102 monozygotic (MZ) and 113 dizygotic (DZ) 63- to 76-yr-old female twin pairs to estimate the mCSA of the lower leg, structural bending strength of the tibial shaft (BSIbend), and compressive strength of the distal tibia (BSIcomp). Quantitative genetic models were used to decompose the phenotypic variances into common and trait-specific additive genetic (A), shared environmental (C), and individual environmental (E) effects. The …

Corrigendum to “Low volumetric BMD is linked to upper-limb fracture in pubertal girls and persists into adulthood: A seven-year cohort study” [Bone 45 (2009) 480-486]

a Department of Health Sciences, University of Jyvaskyla, Jyvaskyla, Finland b Department of Orthopaedics and Traumatology, Kuopio University Hospital, Kuopio, Finland c Department of Preventive Medicine, University of Tennessee Health Science Center, USA d Endocrine Centre, Heidelberg Repatriation Hospital, Austin Health/Department of Medicine, University of Melbourne, Australia e Department of Medical Rehabilitation, Oulu University Hospital and Institute of Health Sciences, University of Oulu, Oulu, Finland

Absence of an aging‐related increase in fibre type grouping in athletes and non‐athletes

The ageing‐related loss of muscle mass is thought to be partly attributable to motor neuron loss and motor unit remodelling that result in fibre type grouping. We examined fibre type grouping in 19‐ to 85‐year‐old athletes and non‐athletes and evaluated to which extent any observed grouping is explained by the fibre type composition of the muscle. Since regular physical activity may stimulate reinnervation, we hypothesised that fibre groups are larger in master athletes than in age‐matched non‐athletes. Fibre type grouping was assessed in m. vastus lateralis biopsies from 22 young (19‐27 years) and 35 healthy older (66‐82 years) non‐athletes, and 14 young (20‐29 years), 51 middle‐aged (38‐6…

Monitoring bone growth using quantitative ultrasound in comparison with DXA and pQCT.

Quantitative ultrasound (QUS) is a safe, inexpensive, and nonradiation method for bone density assessment. QUS correlates with, and predicts fragility fractures comparable to, dual-energy X-ray absorptiometry (DXA)-derived bone mineral density (BMD) in postmenopausal women. However, its validity in monitoring bone growth in children is not well understood. Two hundred and fifty-eight 10-13 yr pubertal girls and 9 37-43 yr adults without diseases or history of medications known to affect bone metabolism were included in the 2-yr prospective study. Calcaneal broadband ultrasound attenuation (cBUA) was assessed using QUS-2 (Quidel, Santa Clara, CA), speed of sound of tibial shaft (tSOS) using …

Collagen of slow twitch and fast twitch muscle fibres in different types of rat skeletal muscle

The appearance of collagen around individual fast twitch (FT) and slow twitch (ST) muscle fibres was investigated in skeletal muscles with different contractile properties using endurance trained and untrained rats as experimental animals. The collagenous connective tissue was analyzed by measuring hydroxyproline biochemically and by staining collagenous material histochemically in M. soleus (MS), M. rectus femoris (MRF), and M. gastrocnemius (MG). The concentration of hydroxyproline in the ST fibres dissected from MS (2.72 +/- 0.35 micrograms X mg-1 d.w.) was significantly higher than that of the FT fibres dissected from MRF (1.52 +/- 0.33 micrograms X mg-1 d.w.). Similarly, the concentrat…

Differential effects of sex hormones on peri- and endocortical bone surfaces in pubertal girls.

Context: The role of sex steroids in bone growth in pubertal girls is not yet clear. Bone biomarkers are indicators of bone metabolic activity, but their value in predicting bone quality has not been studied in growing girls. Objective: This study examines the association of sex hormones and bone markers with bone geometry and density in pubertal girls. Design: The study was designed as a 2-yr longitudinal study in pubertal girls. Measurements were performed at baseline and at 1and 2-yr follow-ups. Setting: The study was conducted in a university laboratory. Participants: A total of 258 10- to 13-yr-old healthy girls at the baseline participated. Methods:Peripheralquantitativecomputedtomogr…

Biomechanical and skeletal muscle determinants of maximum running speed with aging.

Purpose: Aging diminishes the ability to run fast, but the specific mechanisms responsible for this deterioration remain largely unknown. In the present study, we investigated the age-related decline in sprint running ability through a cross-sectional examination of biomechanical and skeletal muscle characteristics in 77 competitive male sprinters aged 17-82 yr. Methods: Ground reaction force (GRF) and kinematic stride cycle parameters were measured during the maximum-velocity phase using a 9.4-m-long force platform. Knee extensor (KE) and ankle plantar flexor (PF) structural characteristics were investigated using ultrasonography and muscle biopsies (vastus lateralis). Force production cha…

Effects of hormone replacement therapy and high-impact physical exercise on skeletal muscle in post-menopausal women: a randomized placebo-controlled study

An age-related decline in muscle performance is a known risk factor for falling, fracture and disability. In women, a clear deterioration is observed from early menopause. The effect of hormone replacement therapy (HRT) in preserving muscle performance is, however, unclear. This trial examined the effects of a 12-month HRT and high-impact physical exercise regimen on skeletal muscle in women in early menopause. A total of 80 women aged 50–57 years were assigned randomly to one of four groups: exercise (Ex), HRT, exercise+HRT (ExHRT) and control (Co). The exercise groups participated in a high-impact training programme. The administration of HRT (oestradiol/noretisterone acetate) or placebo …

Muscle strength and history of heavy manual work among elderly trained women and randomly chosen sample population.

The association between a history of heavy work and muscle strength was studied among 51 physically active women aged 66–85 years trained in sports and 41 women aged 70–81 years selected randomly from the population register. Maximal isometric muscle strength of hand grip, arm flexion, leg extension and trunk flexion and extension were measured using specially constructed dynamometers. The capacity of the abdominal muscles was evaluated by means of a sit-up test. The study included an interview dealing with the subjects' histories of heavy manual employment. The mean histories of heavy work for the trained and untrained women were 24 and 36 years, respectively. The trained women showed sign…

Influence of physical activity and maturation status on bone mass and geometry in early pubertal girls1

This study aimed to evaluate the influence of leisure-time physical activity on the development of bone mass and density in early pubertal girls. Scores of physical activity were obtained from 242 Finnish girls (10-12 years old within Tanner Stages I-II) using a questionnaire. Bone mass and density were assessed using different densitometric techniques. At Tanner Stage I, active girls had significantly higher bone mineral mass (BMC) and areal bone mineral density (aBMD) of the whole body and cortical volumetric BMD and thickness of the tibial shaft compared with sedentary girls (P<0.05). On the other hand, the active girls at Tanner Stage II showed significantly higher values only in BMC an…

Change in bone mass distribution induced by hormone replacement therapy and high-impact physical exercise in post-menopausal women.

The purpose of this intervention trial was to determine whether changes in bone mass distribution could be observed in postmenopausal women following hormone replacement therapy (HRT) and/or high-impact physical exercise. Eighty healthy women, aged 50-57 years, at5 years after the onset of menopause and with no previous use of HRT, were randomly assigned to one of four groups: HRT; exercise (Ex); HRT + Ex (ExHRT); and control (Co). HRT administration was conducted in a double-blind manner for 1 year using estradiol plus noretisterone acetate (Kliogest). The exercise groups participated in a 1 year progressive training program consisting of jumping and bounding activities. Subjects participa…

Leisure-time physical activity and high-risk fat: a longitudinal population-based twin study.

Exercise is thought to reduce high-risk body fat, but intervention studies are frequently limited by short follow-ups and observational studies by genetic selection. Therefore, we studied the effects of a physically inactive vs active lifestyle on high-risk (visceral, liver and intramuscular) fat in twin pairs discordant for leisure-time physical activity habits for over 30 years.A longitudinal population-based twin study.Sixteen middle-aged (50-74 years) same-sex twin pairs (seven monozygotic (MZ), nine dizygotic (DZ)) with long-term discordance for physical activity habits were comprehensively identified from the Finnish Twin Cohort (TWINACTIVE study). Discordance was initially defined in…

Which muscles compromise human locomotor performance with age?

Ageing leads to a progressive decline in human locomotor performance. However, it is not known whether this decline results from reduced joint moment and power generation of all lower limb muscle groups or just some of them. To further our understanding of age-related locomotor decline, we compare the amounts of joint moments and powers generated by lower limb muscles during walking (self-selected), running (4 m s −1 ) and sprinting (maximal speed) among young, middle-aged and old adults. We find that age-related deficit in ankle plantarflexor moment and power generation becomes more severe as locomotion change from walking to running to sprinting. As a result, old adults generate more pow…

Risk factors for clinical stress fractures in male military recruits: A prospective cohort study

This prospective study was aimed at evaluating risk factors for symptomatic stress fractures among 179 Finnish male military recruits, aged 18 to 20 years. The subjects were studied in the very beginning of the military service of 6 to 12 months in summer. Bone mineral content (BMC) and density (BMD) were measured by dual energy X-ray absorptiometry (DXA) at the lumbar spine and at the hip and heel ultrasound investigation was performed. Blood was sampled for determination of serum total and free testosterone, total and free estradiol, sex hormone-binding globulin (SHBG), procollagen type I N propeptide, total and carboxylated osteocalcin, tartrate-resistant acid phosphatase 5b, 25-hydroxyv…

Comparison of ultrasound and bone mineral density assessment of the calcaneus with different regions of interest in healthy early menopausal women.

This study investigated the effect of different sized regions of interest (ROIs) on quantitative ultrasound (QUS) variables of the calcaneus. The effect on QUS of using a fixed ROI as opposed to an ROI adjusted for foot length was also assessed. Eighty Caucasian women, aged 50-57 yr (mean 53 +/- 2) who were healthy and within 0. 5-5 yr of the onset of menopause participated in this study. Using the QUS-1(trade mark) Ultrasonometer (Metra Biosystems, Mountain View, CA), we assessed broadband ultrasound attenuation ([BUA] and UBI-4, dB/MHz), the average transit time through the heel ([TTH], mus) and a multiple-factor index (UBI-4T = UBI-4/TTH, dB/[MHz. mus]). The QUS measurement results were …

Sensitivity of the central visual field in 70- to 81-year-old male athletes and in a population sample.

The sensitivity of the central visual field (0°–30°) was studied using an automatic Octopus 500E perimeter in elderly male athletes and in a population sample of men of corresponding age. The athletes (N=96) were endurance and power athletes, who were still active in competitive sports with training histories spanning tens of years. The athletes’ results were compared with those of a sample of men of the same age (70–81 years, N=41) randomly selected from the local population register. The sensitivity values of the athletes, and the endurance athletes in particular, were significantly better than those of the controls, with differences varying from 1 to 2.5 dB in the different areas of the …

Muscle ultrasonography and computed tomography in elderly trained and untrained women

Ultrasonography (US) and computed tomography (CT) were compared in studying the associations between long-term physical training and quadriceps muscle mass and structure in female athletes and controls, aged 66-85 years. Muscle cross-sectional area (CSA) measured using US correlated highly with that measured using CT, but the latter technique yielded 30% higher values on average. The echo intensity of the fasciae and bone measured by US correlated positively with the mean radiological density and negatively with the relative proportion of fat obtained from CT. Low intramuscular echo intensity was accompanied by high muscle density and low relative proportion of fat. The athletes had larger …

Diffusion capacity of the lung in young and old endurance athletes

Lung diffusion capacity (D LCO) declines with age. A significant proportion of older endurance athletes develop exercise-induced hypoxemia (SaO2<95%). We hypothesised that master endurance athletes have a lower D LCO than age-matched non-athletes. We recruited 33 control (16 young; 17 old) and 29 male endurance athletes (13 young; 16 old) during the World Masters Athletics Indoor Championships, 2012 (Jyvaskyla, Finland). To measure D LCO the participant exhaled to residual volume and then quickly inhaled to ≥ 90% total lung capacity from a gas source with 0.3% carbon monoxide. The D LCO and transfer coefficient (K CO) were corrected for the actual haemoglobin concentration. Spirometric func…

Effects of diet-induced obesity and voluntary wheel running on bone mechanical properties from male young C57/6J mice

Ankle and knee extensor muscle effort during locomotion in young and older athletes : Implications for understanding age-related locomotor decline

AbstractAge-related reduction in muscle force generation capacity is similarly evident across different lower limb muscle groups, yet decline in locomotor performance with age has been shown to depend primarily on reduced ankle extensor muscle function. To better understand why ageing has the largest detrimental effect on ankle joint function during locomotion, we examined maximal ankle and knee extensor force development during a two-leg hopping test in older and young men, and used these forces as a reference to calculate relative operating efforts for the knee and ankle extensors as participants walked, ran and sprinted. We found that, across locomotion modes in both age groups, ankle ex…

Effect of bicycle ergometer test on intraocular pressure in elderly athletes and controls.

To evaluate the effect of intensive physical exercise on intraocular pressure (IOP) in 66- to 85-year-old subjects IOP was measured before and after a maximal bicycle ergometer test. The non-glaucomatous subjects comprised 85 males and 36 female athletes and 16 male and 22 female controls of corresponding age drawn from a population register. IOP was measured using a non-contact tonometer. The results indicated a decrease (> or = 2 mmHg) in 34% of the subjects, no change in 57% and an increase in 9%. The decrease was more pronounced in subjects with higher pre-test values. In all four subjects with a pre-test value above 22 mmHg a reduction from 4 to 11 mmHg was observed. The change in IOP …

Effects of combined hormone replacement therapy or its effective agents on the IGF-1 pathway in skeletal muscle.

Objectives To investigate the effects of combined hormone replacement therapy (HRT) and its effective agents on the IGF-1 signaling pathway. Design and methods To examine the effects of HRT on skeletal muscle in vivo, we utilized pre- and post-intervention samples from a randomized double blinded trial with 50–57-year-old women. The intervention included the year-long use of either HRT preparation (2 mg 17β-estradiol, E2; 1 mg norethisterone acetate, NETA, n = 10) or placebo (CO, n = 9). Microarray technology and quantitative PCR (qPCR) were used to study the expression of insulin-like growth factor I (IGF-1) and its splice variants as well as IGF-1 receptor, Akt1, mTOR, FOXO1, FOXO3, atrog…

Age and sex differences in blood lactate response to sprint running in elite master athletes.

The effect of age and sex on anaerobic glycolytic capacity in master athletes is currently unclear. To study this issue, we determined blood lactate concentrations after competitive sprint running in male and female master athletes of different age. Eighty-one men (40-88 yrs) and 75 women (35-87 yrs) participating in the sprint events (100-m, 200-m, 400-m) in the European Veterans Athletics Championships were studied. Blood samples were taken from the fingertip and analysed for peak lactate concentration ([La]bpeak). The [La]bpeak following 100-m to 400-m races showed a curvilinear decline (p &lt;  0.001-0.05) with age in both men and women. However, the age related differences in the [La]b…

Muscle training for bone strength

The main function of bone is to provide the mechanical integrity for locomotion and protection; accordingly, bone mass and architecture are adjusted to control the strains produced by mechanical load and muscular activity. Age-related patterns involve peak bone mass during growth, a plateau in adulthood, and bone loss during aging. The decline in bone mass and structural integrity results in increased risk of fractures, particularly in post-menopausal women. Athletes competing in strength and power events, such as weight-lifting and jumping, have superior bone mass and structure compared with their untrained counterparts in all age groups. Exercise seems to be most effective during rapid gr…

Effect of diet composition on acid–base balance in adolescents, young adults and elderly at rest and during exercise

Diets rich in animal protein and cereal grains and deficient in vegetables and fruits may cause low-grade metabolic acidosis, which may impact exercise and health. We hypothesized that (1) a normal-protein diet with high amount of vegetables and fruits (HV) induces more alkaline acid-base balance compared with a high-protein diet with no vegetables and fruits (HP) and (2) diet composition has a greater impact on acid-base balance in the elderly (ELD).In all, 12-15 (adolescents (ADO)), 25-35 (young adults (YAD)) and 60-75 (ELD)-year-old male and female subjects (n=88) followed a 7-day HV and a 7-day HP in a randomized order and at the end performed incremental cycle ergometer tests. We inves…

Effects of combined strength and sprint training on regulation of muscle contraction at the whole-muscle and single-fibre levels in elite master sprinters

The aims of this study were to investigate the mechanisms underlying (1) the ageing-related motor handicap at the whole muscle, cellular, contractile protein and myonuclear levels; and (2) ageing-related differences in muscle adaptability.In vivo muscles function was studied in the knee extensors. Decreases were observed in isokinetic and isometric torque outputs in old age in the sedentary men and women and elite master sprinters. A 20-week long specific sprint and resistance training successfully improved the maximal isometric force and rate of force development in a subgroup of master sprinters.In vitro measurements were performed in muscle biopsies from the vastus lateralis muscle. Immu…

Effects of calcium, dairy product, and vitamin D supplementation on bone mass accrual and body composition in 10-12-y-old girls: a 2-y randomized trial

Little is known about the relative effectiveness of calcium supplementation from food or pills with or without vitamin D supplementation for bone mass accrual during the rapid growth period.The purpose was to examine the effects of both food-based and pill supplements of calcium and vitamin D on bone mass and body composition in girls aged 10-12 y.This placebo-controlled intervention trial randomly assigned 195 healthy girls at Tanner stage I-II, aged 10-12 y, with dietary calcium intakes900 mg/d to 1 of 4 groups: calcium (1000 mg) + vitamin D3 (200 IU), calcium (1000 mg), cheese (1000 mg calcium), and placebo. Primary outcomes were bone indexes of the hip, spine, and whole body by dual-ene…

Type IV collagen and laminin in slow and fast skeletal muscle in rats--effects of age and life-time endurance training.

The changes in the biochemical composition of basement membrane (BM) in slow-twitch (m. soleus, MS) and fast-twitch (m. rectus femoris, MRF) skeletal muscles of rats were studied during aging and life-time endurance training (treadmill running). The concentrations of the 7S domain of type IV collagen and of the P2 fragment of laminin were determined with radioimmunoassays in the muscles of rats aged 1, 2, 4, 10, and 24 months. The concentration of type IV collagen was higher in MS than in MRF and increased significantly with age. At older ages, the concentration tended to be higher in the MS of trained than untrained rats. The concentration of laminin was significantly higher in MRF than in…

Low volumetric BMD is linked to upper-limb fracture in pubertal girls and persists into adulthood: A seven-year cohort study

Abstract The aetiology of increased incidence of fracture during puberty is unclear. This study aimed to determine whether low volumetric bone mineral density (vBMD) in the distal radius is associated with upper-limb fractures in growing girls, and whether any such vBMD deficit persists into adulthood. Fracture history from birth to 20 years was obtained and verified by medical records in 1034 Finnish girls aged 10–13 years. Bone density and geometry at distal radius, biomarkers and lifestyle/behavioural factors were assessed in a subset of 396 girls with a 7.5-year follow-up. We found that fracture incidence peaked during puberty (relative risk 3.1 at age of 8–14 years compared to outside …

Age-Related Differences in 100-m Sprint Performance in Male and Female Master Runners

This study was undertaken to investigate age-related differences in the velocity and selected stride parameters in male and female master sprinters and to determine which stride characteristics were related to the overall decline in the performance of the 100 m with age.The performances of 70 finalists (males 40-88 yr, females 35-87 yr) at the European Veterans Athletics Championships were recorded using two high-speed cameras (200 Hz) with a panning video technique and distance markers at 10-m intervals. Velocity, stride length (SL), stride rate (SR), ground contact time (CT), and flight time (FT) during the acceleration, peak velocity, and deceleration phases of the 100-m race were determ…

Effects of physical training on metabolism of connective tissues in young mice.

The effects of physical training on the metabolism of collagen, calcium and glycosaminoglycans in various connective tissues were studied in male NMRI mice. The mice to be trained and their controls were about 3 weeks old (expt. I) and 8 weeks old (expt. II) at the commencement of training. The training was performed on a 5 degree inclined treadmill 5 days a week for 4 weeks in expt. I and for 3 weeks in expt. II. The daily exercise time was progressively increased from 20 min in the first week up to 80 min in the third week. The incorporation of 3H-proline to collagen hydroxyproline was increased by training in long bones, skeletal muscle and Achilles tendon, whereas the incorporation of 3…

Effects of a 20-week high-intensity strength and sprint training program on tibial bone structure and strength in middle-aged and older male sprint athletes: a randomized controlled trial.

This randomized, controlled, high-intensity strength and sprint training trial in middle-aged and older male sprint athletes showed significant improvements in mid-tibial structure and strength. The study reveals the adaptability of aging bone, suggesting that through a novel, intensive training stimulus it is possible to strengthen bones during aging. High-load, high-speed and impact-type exercise may be an efficient way of improving bone strength even in old age. We evaluated the effects of combined strength and sprint training on indices of bone health in competitive masters athletes, who serve as a group of older people who are likely to be able to participate in vigorous exercise of th…

What Makes a 97-Year-Old Man Cycle 5,000 km a Year?

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; The nature versus nurture debate is one of the oldest issues in the study of longevity, health and successful aging. &lt;b&gt;&lt;i&gt;Objective:&lt;/i&gt;&lt;/b&gt; We present a 97-year-old man (I.K.) as an example of the effects of habitual exercise on the aging process. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; Extensive assessments included medical examinations, interviews, musculoskeletal structure, performance characteristics, cognitive function and gut microbiota composition. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; I.K. suffers from iatrogenic hypogonadism, prostate cancer, hypothyroidism and a history of deep popliteal th…

Relationship of sex hormones to bone geometric properties and mineral density in early pubertal girls.

This study aimed to evaluate the associations among serum 17beta-estradiol (E2), testosterone (T), sex hormone-binding globulin (SHBG), bone geometric properties, and mineral density in 248 healthy girls between the ages of 10 and 13 yr old. The left tibial shaft was measured by peripheral quantitative computed tomography (Stratec XCT-2000; Stratec Medizintechnik, GmbH, Pforzheim, Germany). The cortical bone and marrow cavity areas were expressed as proportions of the total tibial cross-sectional area (CSA). Cortical thickness and total volumetric bone mineral density (vBMD) were also determined. These tibial geometric and densitometric measures were correlated against the serum sex hormone…

Blood circulation of long bones in trained growing rats and mice

The effect of physical training on the blood circulation of long bones was studied in growing rats and mice of NMRI-strain. The animals to be trained and their controls were about 2 weeks old at the beginning of the training. The training took place on a 5 degree inclined treadmill 5 days a week for 3 weeks in experiment I and 7 weeks in experiments II and III. The duration of the daily exercise was progressively increased over 3 weeks. The final exercise bouts were 80 min for moderate and 180 min for intensive training programs. The circulating red cell volume (ml/100 g bone) of the humeral, femoral and tibial bones of the trained animals was lower compared to the controls in all three exp…

Age- and training-related changes in the collagen metabolism of rat skeletal muscle

The effects of ageing and life-long endurance training on the collagen metabolism of skeletal muscle were evaluated in a longitudinal study. Wistar rats performed treadmill running 5 days a week for 2 years. The activities of collagen biosynthesis enzymes, prolyl-4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, were highest in the muscles of the youngest animals, decreased up to the age of 2 months and from then on remained virtually unchanged. The enzyme activity in young animals was higher in the slow collagenous soleus muscle than in the rectus femoris muscle. The enzyme activity in the soleus muscle was higher for older trained rats than older untrained rats. The relative p…

Aging, muscle fiber type, and contractile function in sprint-trained athletes

Biopsy samples were taken from the vastus lateralis of 18- to 84-yr-old male sprinters ( n = 91). Fiber-type distribution, cross-sectional area, and myosin heavy chain (MHC) isoform content were identified using ATPase histochemistry and SDS-PAGE. Specific tension and maximum shortening velocity ( Vo) were determined in 144 single skinned fibers from younger (18–33 yr, n = 8) and older (53–77 yr, n = 9) runners. Force-time characteristics of the knee extensors were determined by using isometric contraction. The cross-sectional area of type I fibers was unchanged with age, whereas that of type II fibers was reduced ( P &lt; 0.001). With age there was an increased MHC I ( P &lt; 0.01) and re…

Effects of strength and endurance training on isometric muscle strength and walking speed in elderly women

The separate effects of 18 weeks of intensive strength and endurance training on isometric knee extension (KE) and flexion (KF) strength and walking speed were studied in 76- to 78- year-old women. Maximal voluntary isometric force for both KE and KF was measured in a sitting position on a custom-made dynamometer chair at a knee angle of 60 degrees from full extension. Maximal walking speed was measured over a distance of 10 m. The endurance-trained women increased KE torque and KE torque/body mass after the first 9 weeks of training when compared with the controls. when comparing the baseline, 9 week and 18 week measurements within the groups separately, both the endurance- and strength-tr…

Power training and postmenopausal hormone therapy affect transcriptional control of specific co-regulated gene clusters in skeletal muscle

At the moment, there is no clear molecular explanation for the steeper decline in muscle performance after menopause or the mechanisms of counteractive treatments. The goal of this genome-wide study was to identify the genes and gene clusters through which power training (PT) comprising jumping activities or estrogen containing hormone replacement therapy (HRT) may affect skeletal muscle properties after menopause. We used musculus vastus lateralis samples from early stage postmenopausal (50–57 years old) women participating in a yearlong randomized double-blind placebo-controlled trial with PT and HRT interventions. Using microarray platform with over 24,000 probes, we identified 665 diffe…

Elastic wave propagation in bone in vivo: methodology.

The purpose of this study was to investigate the usefulness of elastic wave propagation (EWP) in estimating the mechanical properties (elasticity) of human tibia. The test group was composed of 78-yr-old women assigned to high (n = 19) and low (n = 17) bone mineral density (BMD) groups as measured at the calcaneus by the 125I-photon absorption method. The EWP apparatus consisted of an impact-producing hammer with a force strain gauge and two accelerometers positioned on the bone. Results for nylon and acrylic were used to calibrate the apparatus. Polyvinyl chloride (PVC) solid rods and tubes of various diameters were used to evaluate the relationship between the elastic wave velocity and cr…

Effect of Eight Weeks' Physical Training on Muscle and Connective Tissue of the M. Vastus Lateralis in 69-year-old Men and Women

Five one-hour exercise periods a week for 8 weeks included walking-jogging, swimming, gymnastics and ballgames for 26 healthy male and female 69-year-old pensioners. The mean maximal oxygen uptake of the men increased from 28.9 ml-kg-1-min-1 before training to 32.0 ml-kg-1-min-1 after training and for the women from 27.9 to 31.3 ml-kg-1-min-1. Muscle malate dehydrogenase activity was increased while that for lactate dehydrogenase decreased or remained the same. The activity of these enzymes was higher in the male both before and after training when compared with the female. However, the percentage number of slow twitch muscle fibers was nearly the same in both groups. Prolyl hydroxylase act…

Ultrasound imaging of the quadriceps muscle in elderly athletes and untrained men.

Ultrasound (US) technique was applied to measure the thickness, cross-sectional area (CSA), and internal structure of the quadriceps muscle in 70- to 80-year-old endurance and power athletes and untrained men. Isometric knee extension strength was higher in the power athletes than in the other groups. The mean values for thickness and CSA did not differ between the athletes and the untrained men. The intensity of the intramuscular echo was, however, lower and the echo reflected from the connective tissue septa and bone was higher in the athletes than in the untrained men. Both the CSA and internal structure of the muscle group correlated significantly with muscle strength and number of trai…

Long Term Leisure Time Physical Activity Has a Positive Effect on Bone Mass Gain in Girls

The purpose of this 7-year prospective longitudinal study was to examine whether the level and consistency of leisure-time physical activity (LTPA) during adolescence affected the bone mineral content (BMC) and bone mineral density (BMD) attained at early adulthood. The study subjects were 202 Finnish girls who were 10 to 13 years of age at baseline. Bone area (BA), BMC, and BMD of the total body (TB), total femur (TF), and lumbar spine (L2–L4) were assessed by dual-energy X-ray absorptiometry (DXA). Scores of LTPA were obtained by questionnaire. Girls were divided into four groups: consistently low physical activity (GLL), consistently high (GHH), and changed from low to high (GLH) and fro…

Effects of diet-induced obesity and voluntary wheel running on the microstructure of the murine distal femur

Abstract Background Obesity and osteoporosis, two possibly related conditions, are rapidly expanding health concerns in modern society. Both of them are associated with sedentary life style and nutrition. To investigate the effects of diet-induced obesity and voluntary physical activity we used high resolution micro-computed tomography (μCT) together with peripheral quantitative computed tomography (pQCT) to examine the microstructure of the distal femoral metaphysis in mice. Methods Forty 7-week-old male C57BL/6J mice were assigned to 4 groups: control (C), control + running (CR), high-fat diet (HF), and high-fat diet + running (HFR). After a 21-week intervention, all the mice were sacrifi…

Physical activity and health: Musculoskeletal issues

Sarcopenia and osteoporosis, the complications of the age-related deterioration of the musculoskeletal system, result in increased risk of fracture, disability and death in old age. Consequently, the structure and function of skeletal muscle and bone and their adaptability are essential aspects of overall health, functional capacity and mobility during the whole lifespan. There is convincing clinical evidence that progressive resistance exercise training improves the properties of skeletal muscle in men and women across the age spectrum, thus providing a high reserve capacity for coping with the functional demands of physical tasks. Regarding bones, exercise is most effective during growth,…

Age-Related Declines in Lower Limb Muscle Function are Similar in Power and Endurance Athletes of Both Sexes : A Longitudinal Study of Master Athletes

The age-related decline in muscle function, particularly muscle power, is associated with increased risk of important clinical outcomes. Physical activity is an important determinant of muscle function, and different types of physical activity e.g. power-based versus endurance-based exercise appear to have differential effects on muscle power. Cross-sectional studies suggest that participation in power-based exercise is associated with greater muscle power across adulthood but this has not been investigated longitudinally. We recruited eighty-nine male and female power and endurance master athletes (sprint and distance runners respectively, baseline age 35–90y). Using jumping mechanography,…

The effect of hormone replacement therapy and/or exercise on skeletal muscle attenuation in postmenopausal women: a yearlong intervention

Hormone replacement therapy (HRT) has been reported to exert a positive effect on preserving muscle strength following the menopause, however, the mechanism of action remains unclear. We examined whether the mechanism involved preservation of muscle composition as determined by skeletal muscle attenuation. Eighty women aged 50-57 years were randomly assigned to either: HRT, exercise (Ex), HRT + exercise (ExHRT), and control (Co) for 1 year. The study was double-blinded with subjects receiving oestradiol and norethisterone acetate (Kliogest) or placebo. Exercise included progressive high-impact training for the lower limbs. Skeletal muscle attenuation in Hounsfield units (HU) was determined …

Bone Mineral Density and Long Term Exercise

Evidence in human studies of the association of long term habitual exercise with bone mineral content (BMC) and density (BMD) largely comes from studies in athletes. In young adults, the highest BMC and BMD values have been found in strength and power-trained athletes, while endurance activities such as long distance running and swimming seem less effective with regard to peak bone density. Intensive endurance training may even be associated with amenorrhoea and decreased trabecular bone density in young females. However, after menopause female athletes show greater bone mass indicating that they do not share the accelerated decline in BMC observed in a nonathletic population. Middle-aged a…

Influence of long-term postmenopausal hormone-replacement therapy on estimated structural bone strength: A study in discordant monozygotic twins

Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT). In the tibial shaft,…

Correlates of vibrotactile thresholds in men of different ages

— As a part of a larger gerontological research project vibrotactile thresholds on the inner malleolus of the ankle were studied in 355 men aged 31–35, 51–55 and 71–75 years. The groups studied were random samples of men living in the town of Jyvaskyla in Finland in the year 1981. The thresholds were assessed at three frequencies: 50 Hz, 100 Hz and 250 Hz. The thresholds were associated with age at all frequencies, the means of the threshold values being significantly higher in the older age groups. Within the age groups the thresholds correlated positively with height. In addition, reaction and movement time, leg extension velocity, and postural sway were associated with the thresholds. Ne…

Influence of long-term postmenopausal hormone replacement therapy on estimated structural bone strength: A study in discordant monozygotic twins.

Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT). In the tibial shaft,…

Effects of 8 weeks' endurance training on skeletal muscle metabolism in 56?70-year-old sedentary men

The effects of 8 weeks' endurance training on muscle metabolism at rest and after a submaximal bicycle ergometer exercise were studied in 31 previously sedentary men, aged 56-70. Training consisted of 3-5 one hour exercise bouts per week including walking-jogging, swimming, gymnastics and ball games. The effects of training were similar to those previously reported for younger men. Mean maximal oxygen uptake increased (11%), as did the resting values for muscle glycogen concentration, the enzymes representing aerobic energy metabolism (malate dehydrogenase, succinate dehydrogenase), and also some of the anaerobic enzymes (creatine phosphokinase, lactate dehydrogenase). Lactate production du…

Maximal isometric muscle strength and anthropometry in 75-year-old men and women in three Nordic localities

Isometric maximal strength of hand grip, elbow flexion, knee extension, trunk extension and trunk flexion was studied in representative samples of 75-year-old residents of 3 Nordic localities: Glostrup in Denmark, Gothenburg in Sweden and Jyvaskyla in Finland. The study forms a part of a wider comparative research project analyzing the functional capacity and health of 75-year-olds in these towns. The strength measurements were carried out using standardized techniques and identical dynamometers. The results showed that the strength values of the limb muscles were significantly lower among the 75-year-olds in Jyvaskyla, both in absolute values and in relative units (N/kg body mass). For the…

Bone mineral density and physical activity in 50–60-year-old women

Abstract The bone mineral density (BMD) of the calcaneus was measured utilizing a single energy photon absorption method in 108 women, aged 50–60 years. The women who participated in vigorous exercise two or more times a week or whose total physical activity amounted to 4 h a week had significantly higher BMD values than those who exercised less than two times a week or did less than 4 h physical activity a week. The physically active women also showed higher values for leg extension force and maximal oxygen uptake. BMD and leg extension force were positively correlated, whereas correlations between BMD and body mass, and the width of the calcaneus were negative. When other life-style varia…

Oral health and reduction in respiratory capacity in a cohort of community-dwelling elderly people: a population-based 5-year follow-up study.

Objectives:  Several anaerobic bacteria originating in periodontal pockets have been isolated from infected lungs and pharyngeal microflora. Increased bacterial load in lungs is known to be a risk factor for decline in forced expiratory volume during the first second. The aim was to evaluate both cross-sectionally and longitudinally the association between oral health status and forced expiratory volume during the first second (FEV1) in older residents of the city of Jyvaskyla, Finland. Design:  Cross-sectional and prospective cohort study over a 5-year follow-up. Setting:  Research laboratory of the University of Jyvaskyla. Participants:  In 1990 dental status and FEV1 were examined in 203…

Dietary acid load and renal function have varying effects on blood acid-base status and exercise performance across age and gender

Diet composition influences acid-base status of the body. This may become more relevant as renal functional capacity declines with aging. We examined the effects of low (LD) versus high dietary acid load (HD) on blood acid-base status and exercise performance. Participants included 22 adolescents, 33 young adults (YA), and 33 elderly (EL), who followed a 7-day LD and HD in a randomized order. At the end of both diet periods the subjects performed a cycle ergometer test (3 × 10 min at 35%, 55%, 75%, and (except EL) until exhaustion at 100% of maximal oxygen uptake). At the beginning of and after the diet periods, blood samples were collected at rest and after all workloads. Oxygen uptake, re…

Randomized, Double-Blind, Clinically Controlled Trial of Intranasal Calcitonin Treatment in Patients with Hip Fracture

The objective of this study was to evaluate the short-term outcome of intranasal calcitonin treatment of elderly hip fracture patients on pain, bone loss, functional recovery, and length of hospital stay. In addition, we wanted to compare the effect of calcitonin with placebo on fusion of hip fractures treated with internal fixation using a screw or a nail. In a randomized, double-blind, clinically controlled trial, 260 independently living patients (aged 65 years or older) with acute hip fracture were randomly assigned to intranasal calcitonin 200 IU daily for 3 months or matching placebo nasal spray. Analyses were completed on an intention-to-treat basis. Three months after the operation,…

Enzyme activities in muscle and connective tissue of M. vastus lateralis in habitually training and sedentary 33 to 70-year-old men

A cross-sectional study was carried out to examine the activities of certain enzymes representing aerobic and anaerobic energy metabolism as well as the biosynthesis of collagen of M. vastus lateralis in 23 male endurance athletes in habitual training, aged 33 to 70 years. 23 sedentary healthy men of corresponding ages were selected for the control group. The mean maximal oxygen uptake of the trained subjects was 53.6 ml · kg−1 · min−1 and that of the control subjects 36.3 ml · kg−1 · min−1. As compared to the control group the trained subjects had significantly higher values in the muscle malate dehydrogenase, succinate dehydrogenase and prolyl hydroxylase activities, whereas the opposite …

Effect of Physical Training on Enzyme Activities of Bones, Tendons and Skeletal Muscles in Mice

According to several recent papers the activity of some enzymes of energy yielding metabolic pathways increases by endurance training in muscles, but it is not yet known whether similar changes occur also in connective tissues. Some structural, chemical, physical and metabolic changes, however, appear in connective tissues during adaptation to physical exercise. Physical training produces hypertrophy of e.g. tendon and articular cartilage in young rabbits [6] and increases the tensile strength of tendons and breaking strength of bones in growing mice [7]. The level of physical activity affects the turnover of collagen in long bones and Achilles tendons of mice [4] and also affects the miner…

Weight-bearing, muscle loading and bone mineral accrual in pubertal girls--a 2-year longitudinal study.

Abstract Objectives: The mechanical environment is considered to be the most important determinant of bone strength. Local muscle force, in turn, is regarded as the largest source of loading applied to bones. However, the effect of weight-bearing on bone mineral accrual is unclear. Comparing the relationship between muscle force and bone mineral content (BMC) in the upper and lower limbs provides a means of investigating this issue. Subjects and methods : The study group comprised 258 healthy girls aged 10–13 years old at baseline. BMC, lean body mass (LM) and fat body mass (FM) of total body were assessed by dual-energy X-ray absorptiometry at baseline and 2 years after. The maximal isomet…

Effects of strength and endurance training on muscle fibrecharacteristics in elderly women

The effects of 18 weeks' intensive strength and endurance training on fibre characteristics of the vastus lateralis muscle were studied in 76- to 78-year-old women. Type I and type IIa fibres constituted over 90% of the cell population and were almost equally represented. No changes were observed in the proportions of the different fibre types. When comparing the baseline and the 18-week measurements within the groups, the strength group showed a mean increase of 34% (P = 0.028) in mean type I fibre area. The frequency histograms showed an increased proportion of larger type I fibres after strength training and a decreased proportion of smaller type IIa fibres after endurance training. In t…

Genetic and Environmental Influence on Structural Strength of Weight-Bearing and Non-Weight-Bearing Bone: A Twin Study

A bivariate genetic analysis among 217 older female twin pairs showed that, although the structural strength of tibia and radius are mainly regulated by same genetic and environmental factors, the tibia is more affected by environment. Introduction: The habitual loading environment of the bone may modulate the relative contribution of genetic and environmental factors to bone structure. The purpose of this study was to estimate the contribution of the common and site-specific genetic and environmental factors to interindividual variation in compressive structural strength of the weight-bearing tibia and non–weight-bearing radius. Materials and Methods: pQCT scans were obtained from both mem…

Differential influence of peripheral and systemic sex steroids on skeletal muscle quality in pre- and postmenopausal women

Aging is associated with gradual decline of skeletal muscle strength and mass often leading to diminished muscle quality. This phenomenon is known as sarcopenia and affects about 30% of the over 60-year-old population. Androgens act as anabolic agents regulating muscle mass and improving muscle performance. The role of female sex steroids as well as the ability of skeletal muscle tissue to locally produce sex steroids has been less extensively studied. We show that despite the extensive systemic deficit of sex steroid hormones in postmenopausal compared to premenopausal women, the hormone content of skeletal muscle does not follow the same trend. In contrast to the systemic levels, muscle t…

Variability and Symmetry of Force Platform Variables in Maximum-Speed Running in Young and Older Athletes

Eighteen young (23 ± 4 yr) and 25 older (70 ± 4 yr) male sprinters were examined for ground reaction force (GRF) and temporal-spatial variables. The data were collected during maximum-speed phase, and variability and symmetry indices were calculated from a total of 8 steps. There was little variation (CV &lt; 6%) in vertical and resultant GRF and kinematic variables, while impact loading had high variability (CV: 10–21%). Overall, the pattern of variability was similar in both groups. Yet, a small but significant age-related increase in CV was evident in horizontal GRFs. There was a variable-specific asymmetry between legs but it was not related to leg dominance. No age differences existed …

Physical Activity and Exercise in the Maintenance of the Adult Skeleton and the Prevention of Osteoporotic Fractures

Abstract Physical activity and exercise are promoted as a nonpharmacological strategy to maintain or enhance musculoskeletal health in adults and prevent osteoporotic fracture. Less clear is the optimal mode, intensity, duration, and frequency of activity to achieve this objective. Although a substantial osteogenic response to appropriate mechanical loading is clearly evident in animal models and strongly supported from athlete cross-sectional and prospective studies, the results from exercise interventions in adults are less impressive with modest net benefits generally of 1% to 3% in bone mineral density (BMD) (g/cm2) at the clinically relevant hip and spine following prolonged weight-bea…

Whole body frontal plane mechanics across walking, running, and sprinting in young and older adults

This study investigated the whole body frontal plane mechanics among young (26 ± 6 years), early old (61 ± 5 years), and old (78 ± 4 years) adults during walking, running, and sprinting. The age-groups had similar walking (1.6 m/s) and running (4.0 m/s) speeds, but different maximal sprinting speed (young 9.3 m/s, early old 7.9 m/s, and old 6.6 m/s). Surprisingly, although the old group exerted much lower vertical ground reaction force during running and sprinting, the hip frontal plane moment did not differ between the age-groups. Kinematic analysis demonstrated increased hip adduction and pelvis drop, as well as reduced trunk lateral flexion among old adults, especially during sprinting. …

Bone mineral density of the calcaneus in 70??? to 81-yr-old male athletes and a population sample

Bone mineral content (BMC/W) and density (BMD) were studied in 70- to 81-yr-old active male endurance-trained (long-distance runners, cross-country skiers, N = 67), strength-trained (throwers, weight-lifters, N = 14), and speed-trained (sprinters, jumpers, N = 16) athletes. A population sample of similar age (N = 42) served as a control group. The measurements were performed at the calcaneus by single-energy photon absorption. The endurance-trained athletes had higher bone width and depth, and the strength and speed-trained athletes higher bone depth than the control subjects. The three groups of athletes showed 19-28% higher BMC (g.cm-1) and BMC/W (g.cm-2) than the control group (P less th…

Connective tissue of “fast” and “slow” skeletal muscle in rats…effects of endurance training

The connective tissue of two skeletal muscles having different contractile properties was investigated in trained and untrained rats. The animals to be trained were put to run on a treadmill 5 days a week for 4 weeks. The "slow" m. soleus (MS) showed higher malate dehydrogenase activity but lower lactate dehydrogenase activity compared to the "fast" m. rectus femoris (MRF). When whole muscles were taken into account, the concentrations of both hydroxyproline and hexosamines were higher for MS compared to MRF. In the middle section of MS there were more hexosamines than in that of MRF, but no similar difference existed in hydroxyproline. The histochemical staining of collagen, however, sugge…

Endogenous Hormones, Muscle Strength, and Risk of Fall-Related Fractures in Older Women

Background. Among older people, fracture-causing fall often leads to health deterioration. The role of endogenous hormone status and muscle strength on fall-related fracture risk is unclear. This study investigates if, after adjustment for bone density, endogenous hormones and muscle strength would predict fall-related limb fracture incidence in older community-dwelling women followed-up over 10 years. Methods. As a part of a prospective population-based study, 187 75-year-old women were investigated. Serum estradiol, testosterone, sex hormone binding globulin, and dehydroepiandrosterone sulfate concentrations were analyzed, and isometric muscle strength and bone mineral density were assess…

Bone mineral density in relation to anthropometric properties, physical activity and smoking in 75-year-old men and women

Bone mineral content (BMC, gem−2) and density (BMD, gem−3) were studied in 75-year-old men and women in relation to anthropometric and certain life-style factors. This study covered all the men and women born in 1914 who were residents in the city of Jyvaskyla in 1989 (N=388). A hundred and three men and 188 women participated in bone measurements performed at the calcaneus using a 125I-photon absorption method. BMC was on average 36% and BMD 17% higher in the men than in the women. BMC and BMD associated with body mass in both sexes, and with body fat and use of estrogen in the women. There was a negative correlation between the BMD values and the number of cigarettes smoked over the entir…

Tartrate-Resistant Acid Phosphatase 5b: A Novel Serum Marker of Bone Resorption

Human serum contains two forms of tartrate-resistant acid phosphatase (TRAP), 5a and 5b. Of these, 5a contains sialic acid and 5b does not. We show here that antigenic properties and pH optimum of TRAP purified from human osteoclasts are identical to those of serum TRAP 5b and completely different from those of serum TRAP 5a, suggesting that 5b would be derived from osteoclasts and 5a from some other source. We developed a novel immunoassay specific for 5b using a monoclonal antibody O1A as capture antibody. O1A did not bind acid phosphatase derived from platelets and erythrocytes. Western analysis showed that O1A was specific for TRAP in both human bone and serum. We measured bound TRAP ac…

Effects of diet-induced obesity and voluntary wheel running on the microstructure of the murine distal femur

Background. Obesity and osteoporosis, two possibly related conditions, are rapidly expanding health concerns in modern society. Both of them are associated with sedentary life style and nutrition. To investigate the effects of diet-induced obesity and voluntary physical activity we used high resolution micro-computed tomography (μCT) together with peripheral quantitative computed tomography (pQCT) to examine the microstructure of the distal femoral metaphysis in mice. Methods. Forty 7-week-old male C57BL/6J mice were assigned to 4 groups: control (C), control + running (CR), high-fat diet (HF), and high-fat diet + running (HFR). After a 21-week intervention, all the mice were sacrificed and…