Search results for "isometric"
showing 10 items of 535 documents
Allometrically scaled explosive strength, but not static strength or maximal oxygen uptake is associated with better central processing time in young…
2020
BACKGROUND: We aimed to examine the associations of cardiorespiratory fitness (CRF), static strength and explosive strength with cognitive functions in young males. METHODS: Eighty-six young males (age 16-24 years) participated in the study and took part in a number of tests including: static strength (grip strength test), explosive strength (Sargent jump test), and CRF (via direct measure of maximal oxygen uptake (VO2max)). Static strength and explosive strength were scaled by allometrically modeled skeletal muscle mass (SMM) and height while VO2max was scaled by SMM and body mass (BM). Cognition was assessed by inhibitory control, simple and choice reaction time tasks using computerized C…
Muscle Activity During Unilateral vs. Bilateral Battle Rope Exercises.
2015
High training intensity is important for efficient strength gains. Although battle rope training is metabolically demanding, no studies have quantified intensity of muscle activity during this type of training. This study analyzes muscle activity during unilateral alternating waves vs. bilateral waves of battle rope training. Twenty-one volunteers participated in a repeated-measures study on 2 different occasions. Surface electromyographic signals were recorded from the anterior deltoid (AD), external oblique (OBLIQ), lumbar erector spinae (LUMB), and gluteus medius (GM) during bilateral waves and unilateral waves and were normalized to the maximum voluntary isometric contraction (MVIC). Re…
Associations of sensory-motor functions with poor mobility in 75- and 80-year-old people
1998
This study investigated the associations of sensory-motor functions with mobility in elderly people. All 75- and 80-year-old residents of the city of Jyväskylä, Finland, were invited to take part in the study. A total of 617 (93 % ) persons were interviewed, and 500 (75%) took part in laboratory examinations. Self-reported mobility was recorded during the interview. Basic mobility functions (maximal walking speed and stairmounting ability) and sensory-motor functions (maximal isometric muscle strength, standing balance, reaction time and visual acuity) were measured in the laboratory. Multivariate analyses showed that poor sensory-motor functions were significantly associated with poor perf…
Association between lower extremity muscle strength and acute ankle injury in youth team-sports athletes
2021
Abstract Objectives To investigate lower extremity muscle strength as risk factor for an acute ankle injury in youth athletes. Design Cohort study. Setting Basketball and floorball clubs. Participants 188 youth (≤21) male and 174 female athletes. Main outcome measures 1RM leg press, maximal concentric isokinetic quadriceps and hamstrings as well as maximal isometric hip abductor strength were measured and athletes were followed for an acute ankle injury up to three years. Cox regression models were used in statistical analyses. Results In males, greater 1RM leg press and maximal quadriceps strength increased the risk of any type of acute ankle injury (Hazard ratio [HR] for 1 SD increase, 1.…
Strength, [corrected] endurance or combined training elicit diverse skeletal muscle myosin heavy chain isoform proportion but unaltered androgen rece…
2009
We investigated whether the myosin heavy chain (MyHC) proportion and androgen receptor (AR) concentration in skeletal muscle differ following 21 weeks of strength, endurance and combined training in untrained older men. Strength (S) and endurance (E) groups trained twice per week and combined (S+E) group trained four times per week (two strength and two endurance). Muscle biopsies were obtained before and after the training period from m. vastus lateralis (VL) and AR mRNA and protein concentration and MyHC proportion were determined. 1RM increased during the training period in S, S+E and E but the changes were greater in S and S+E than in E. Statistically significant increases were observed…
Effects of resistance training on lower-extremity impairments in older people with hip fracture
2008
Abstract Portegijs E, Kallinen M, Rantanen T, Heinonen A, Sihvonen S, Alen M, Kiviranta I, Sipila S. Effects of resistance training on lower-extremity impairments in older people with hip fracture. Objective To study the effects of resistance training on muscle strength parameters, mobility, and balance. Design Randomized controlled trial. Setting Research laboratory and senior gym. Participants Population-based sample of eligible 60- to 85-year-old community-dwelling men and women 0.5 to 7.0 years after hip fracture. Forty-six people had no contraindications and were willing to participate in the exercise trial. Intervention Twelve-week intensive progressive strength-power training (n=24),…
Transcranial direct current stimulation improves isometric time to exhaustion of the knee extensors
2016
International audience; Transcranial direct current stimulation (tDCS) can increase cortical excitability of a targeted brain area, which may affect endurance exercise performance. However, optimal electrode placement for tDCS remains unclear. We tested the effect of two different tDCS electrode montages for improving exercise performance. Nine subjects underwent a control (CON), placebo (SHAM) and two different tDCS montage sessions in a randomized design. In one tDCS session, the anodal electrode was placed over the left motor cortex and the cathodal on contralateral forehead (HEAD), while for the other montage the anodal electrode was placed over the left motor cortex and cathodal electr…
Changes in cortico-spinal excitability following uphill versus downhill treadmill exercise
2017
International audience; An acute bout of aerobic exercise induces neuroplasticity in the motor cortex. Moreover, paired associative stimulation (PAS) is known to induce neuroplasticity in M1. However, the possible influence of the type of exercise on the neuroplastic changes remains unknown. The present study investigated the effects of two different modes of muscle contraction produced during locomotor exercise on changes in corticospinal (CS) excitability. Subjects performed two 30-min treadmill exercises at an intensity corresponding to 60% of their maximal heart rate with either a +10% (uphill) or -10% (downhill) slope. These exercises were followed or not by paired associative stimulat…
Whey proteins are more efficient than casein in the recovery of muscle functional properties following a casting induced muscle atrophy.
2013
International audience; The purpose of this study was to investigate the effect of whey supplementation, as compared to the standard casein diet, on the recovery of muscle functional properties after a casting-induced immobilization period. After an initial (I0) evaluation of the contractile properties of the plantarflexors (isometric torque-frequency relationship, concentric power-velocity relationship and a fatigability test), the ankle of 20 male adult rats was immobilized by casting for 8 days. During this period, rats were fed a standard diet with 13% of casein (CAS). After cast removal, rats received either the same diet or a diet with 13% of whey proteins (WHEY). A control group (n =…
Neuromuscular Performance and Hormonal Profile During Military Training and Subsequent Recovery Period.
2018
INTRODUCTION Military training loads may induce different physiological responses in garrison and field training and only a little is known about how short-time recovery, lasting a few days, affects neuromuscular fitness and hormonal profile. This study aimed to investigate the effects of garrison and field military service on neuromuscular performance and hormonal profile and to evaluate the effects of a 3-day recovery on those factors. METHODS Twenty healthy male soldiers (20 ± 1 years) participated in the study, which consisted of 4 days of garrison training [days (D) 1-4] and 7 days of military field training (Days 5-12) followed by a 3-day recovery period (Day 15). Serum hormone concen…