Search results for "physical exertion"
showing 10 items of 204 documents
Delayed Anaerobic Threshold in Heart Failure Patients With Atrial Fibrillation
2016
PURPOSE To assess whether atrial fibrillation (AF) in heart failure (HF) affects oxygen uptake at anaerobic threshold ((Equation is included in full-text article.)O2 AT) and heart rate (HR) kinetics. METHODS A total of 15 patients with HF and AF and 18 with HF and sinus rhythm (SR) performed a maximal incremental and 2 constant workload cycle ergometer cardiopulmonary exercise tests (below and above AT, at 25% and 75% of maximal workload, respectively). At constant workload tests, kinetics of (Equation is included in full-text article.)O2 and HR were assessed by calculating time constant (τ). RESULTS HF patients with AF showed a similar peak (Equation is included in full-text article.)O2 to…
Genetic variation in neuromuscular performance.
1973
Using a simple cumulative model of heredity plus environment, based on intrapair differences observed in monozygous (MZ) and dizygous (DZ) twins, the relative contribution of heredity to the interindividual variance in several neuromuscular parameters was determined with 15 pairs of male (8 MZ and 7 DZ) and 14 pairs of female (7 MZ and 7 DZ) twins ranging in age from 10 to 14 years. The data disclosed that in boys the variability in maximal mechanical (anaerobic) power was 99.2% genetically determined under the environmental conditions of the study. The corresponding heritability estimate values for the patellar reflex time and reaction time were 97.5% and 85.7%, respectively. In girls the …
Evaluation of occupational physical load during 6-month international crisis management operation
2018
Objectives Generally, operational military duties are associated with a variety of stressors, such as prolonged physical activity (PA). However, limited information is available on the occupational workload or changes in PA during international military operations. Thus, the aim of the study was to investigate the changes in body composition, stress biomarkers, PA, and heart rate (HR) responses of 79 male soldiers during a 6-month international crisis management operation. Material and Methods Measurements were conducted 3 times in South-Lebanon during the operation. Body composition was assessed by the bioelectrical impedance method. Blood samples were analyzed for serum testosterone, sex-…
Composites of perfectionism and inauthenticity in relation to controlled motivation, performance anxiety and exhaustion among elite junior performers.
2020
The present study identified profiles of perfectionism and inauthenticity at baseline and tested whether they differed in the maladaptive outcomes of controlled motivation, performance anxiety, and exhaustion after a nine-month period. We purposefully selected elite junior performers (NT1 = 219; NT2 = 156), 16–19 years of age, from Norwegian talent development schools in sports and performing arts. The participants completed questionnaires to report their perceptions of the study variables. The results of the latent profile analysis indicated a multidimensionality of perfectionism, thereby identifying four profiles. Although our identified profiles are in line with the 2×2 model of perfecti…
Comparison of Exclusive Double Poling to Classic Techniques of Cross-country Skiing
2018
Introduction: This study aimed to 1) determine basic physiological demands during a simulated on-snow cross-country skiing (XCS) race when using grip-waxed skis (all classic XCS techniques [CLASSIC]), versus glide-waxed skis for exclusive double poling (DP) and 2) analyze in which track sections DP is different from CLASSIC under controlled gliding conditions in elite junior and senior skiers. Methods: Nineteen male and female elite XC skiers performed 1) two randomized simulated XCS races over 5.3 km using DP or CLASSIC measuring section times, V˙ O2, HR, blood lactate, and RPE; and 2) V˙ O2peak tests using diagonal stride and DP on treadmill. Results: The total group showed no differences…
Objectively measured physical activity in Finnish employees: a cross-sectional study.
2014
Objectives: To objectively measure the amount of intensity-specific physical activity by gender and age with respect to body mass index (BMI) during workdays and days off among Finnish employees. Design: A cross-sectional study. Setting: Primary care occupational healthcare units. Participants: A sample of 9554 Finnish employees (4221 men and 5333 women; age range 18–65 years; BMI range 18.5–40 kg/m2) who participated in health assessments related to occupational health promotion. Main outcome measurements: The amount of moderate-to-vigorous (MVPA) and vigorous (VPA) physical activity (≥3 and ≥6 metabolic equivalents, respectively) was assessed by estimating the minuteto-minute oxygen consu…
Xanthine oxidase is involved in exercise-induced oxidative stress in chronic obstructive pulmonary disease
1999
In the present study, we hypothesized that exhaustive exercise in patients with chronic obstructive pulmonary disease (COPD) results in glutathione oxidation and lipid peroxidation and that xanthine oxidase (XO) contributes to free radical generation during exercise. COPD patients performed incremental cycle ergometry until exhaustion with (n = 8) or without (n = 8) prior treatment with allopurinol, an XO inhibitor. Reduced (GSH) and oxidized glutathione (GSSG) and lipid peroxides [malondialdehyde (MDA)] were measured in arterial blood. In nontreated COPD patients, maximal exercise (approximately 75 W) resulted in a significant increase in the GSSG-to-GSH ratio (4. 6 +/- 0.9% at rest vs. 9.…
Relationship between the practice of physical activity and quality of movement in adolescents: a screening tool using self-organizing maps.
2017
The aim of this study was to determine whether the most physically active adolescents have better lower limb control.31 high school students (12 males and 19 females) participated in this study. The Anterior Knee Pain Scale was used to find any cases of knee pain. Only subjects with high scores were selected, to exclude those with knee pain or lower limb injuries. Single Leg Squat and Tuck Jump Assessment were used to evaluate movements with two cameras in a two-dimensional assessment. The IPAQ Questionnaire was used to score the physical activity and to classify it into MET total, MET moderate activity, MET vigorous activity and MET walking. These scores were related to knee angle at landi…
Mechanical jumping power in young athletes.
1987
Mechanical jumping power was determined for 286 young male athletes representing six sports events and ranging in calendar and skeletal ages from 8.8 to 17.1 and from 7.8 to 18.1 years, respectively. The subjects performed successive maximal vertical jumps on a contact mat for 30 s. The number of jumps and their cumulative flight time after 15 and 30 s were used for calculations of mechanical power. The jumping performances of the young athletes were found to be reproducible from the age of 10-12 years in respect to the angular displacement of the knee and duration of contact. Absolute mechanical power, as well as power related to body weight, increased with calendar and skeletal ages. Of t…
Effect of isometric strength training of mechanical, electrical, and metabolic aspects of muscle function.
1978
Monozygous twin pairs (two female and four male) were used in a strength training study so that one member of each pair served as training subject (TS) and the other members as nonexercising controls (CS). TS trained four times a week for 12 weeks with maximal isometric knee extensions of the right leg. The parameters studied included muscle strength, endurance time, electromyographic activity, and activities of several key enzymes in nonoxidative and oxidative muscle metabolism. The results disclosed that in addition to a 20% increase in isometric knee extension strength in the trained leg of TS, an average increase of 11% was observed in strength of TS untrained leg. CS did not demonstrat…