Search results for "Skeletal"
showing 10 items of 3025 documents
Are postural responses to backward and forward perturbations processed by different neural circuits?
2013
Item does not contain fulltext Startle pathways may contribute to rapid accomplishment of postural stability. Here we investigate the possible influence of a startling auditory stimulus (SAS) on postural responses. We formulated four specific questions: (1) can a concurrent SAS shorten the onset of automatic postural responses?; and if so (2) is this effect different for forward versus backward perturbations?; (3) does this effect depend on prior knowledge of the perturbation direction?; and (4) is this effect different for low- and high-magnitude perturbations? Balance was perturbed in 11 healthy participants by a movable platform that suddenly translated forward or backward. Each particip…
Plantarflexor muscle function in healthy and chronic Achilles tendon pain subjects evaluated by the use of EMG and PET imaging
2014
article i nfo Article history: Received 14 October 2013 Accepted 11 March 2014 18 F)-Fluorodeoxyglucose Background: Achilles tendon pathologies may alter the coordinative strategies of synergistic calf muscles. We hypothesized that both surface electromyography and positron emission tomography would reveal differences between symptomatic and asymptomatic legs in Achilles tendinopathy patients and between healthy controls. Methods: Eleven subjects with unilateral chronic Achilles tendon pain (28 years) and eleven matched controls (28 years) were studied for triceps surae and flexor hallucis longus muscle activity in response to repetitive iso- metric plantarflexion tasks performed at 30% of …
Exercise with TENS does not augment gains in balance and strength for dancers
2020
Abstract Electrical stimulation modulates sensory feedback and improves motor performance, at least for individuals with compromised sensorimotor function. The purpose of this study was to determine the effectiveness of a 4-wk intervention with transcutaneous electrical nerve stimulation (TENS) at improving strength and balance in dancers. Nineteen dancers completed a timed, single-leg balance test, the Y-balance test, and contractions with the hip flexor and knee extensor muscles to assess maximal strength and force steadiness. They completed 4-wks of moderate-intensity bodyweight exercises (3x/wk) and were pseudo-randomized to either a Treatment or Sham group in a single-blind design. The…
Strength and Power Characteristics in National Amateur Rugby Players
2021
Rugby players need muscular strength and power to meet the demands of the sport
Acute responses of comprehensive gonadosteroids and corticosteroids to resistance exercise before and after 10 weeks of supervised strength training
2019
New Findings: What is the central question of this study? Although acute responses of the principal gonadosteroid and corticosteroid hormones to resistance exercise are well documented, there is no information regarding how the key lower-concentration intermediary hormones respond and potentially influence these hormonal pathways. What is the main finding and its importance? This study provides evidence for cascading conversions of some gonadosteroids, and the data suggest that the testosterone concentration increases independently of these hormones. These findings challenge future studies to determine the exact physiological roles of the lower-concentration gonadosteroids and corticosteroi…
Effects of a Heart Rate–Based Recovery Period on Hormonal, Neuromuscular, and Aerobic Performance Responses During 7 Weeks of Strength Training in Men
2011
The purpose of this study was to compare hormonal, neuromuscular, and aerobic performance changes between a constant 2-minute interset recovery time and an interset recovery time based on individual heart rate (HR) responses during a 7-week (3 sessions per week, 3 × 10 repetition maximum [RM]) hypertrophic strength training period. The HR-dependent recovery time was determined with a Polar FT80 HR monitor, whereas the control groups used constant 2-minute periods between sets. From 24 male subjects who were divided in 2 equal groups, 21 completed the study (FT80, n = 12; CONTROL, n = 9). Serum blood samples analyzed for testosterone (TES) and cortisol (COR) were taken before and after the 7…
Short vs. Long Rest Period Between the Sets in Hypertrophic Resistance Training: Influence on Muscle Strength, Size, and Hormonal Adaptations in Trai…
2005
Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magneti…
Acute hormonal responses to heavy resistance exercise in strength athletes versus nonathletes.
2004
The aim of the present study was to investigate acute hormonal and neuromuscular responses and recovery in strength athletes versus nonathletes during heavy resistance exercise performed with the forced and maximum repetitions training protocol. Eight male strength athletes (SA) with several years of continuous resistance training experience and 8 physically active but non-strength athletes (NA) volunteered as subjects. The experimental design comprised two loading sessions: maximum repetitions (MR) and forced repetitions (FR). MR included 12-RM squats for 4 sets with a 2-min recovery between sets. In FR the initial load was higher than in MR so that the subject could lift approximately 8 …
Maximal strength and power, muscle mass, endurance and serum hormones in weightlifters and road cyclists.
2004
Maximal strength, power, muscle cross-sectional area, maximal and submaximal cycling endurance characteristics and serum hormone concentrations of testosterone, free testosterone and cortisol were examined in three groups of men: weightlifters (n = 11), amateur road cyclists (n = 18) and age-matched controls (n = 12). Weightlifters showed 45-55% higher power values than road cyclists and controls, whereas the differences in maximal strength and muscle mass were only 15% and 20%, respectively. These differences were maintained when average power output was expressed relative to body mass or relative to muscle cross-sectional area. Road cyclists recorded 44% higher maximal workloads, whereas …
Effects of HRV-Guided vs. Predetermined Block Training on Performance, HRV and Serum Hormones
2017
AbstractThe aim of this study was to compare heart rate variability -guided (HRVG) and predetermined (PD) block periodization of high intensity aerobic training (HIT). Endurance performance, neuromuscular performance, heart rate variability (HRV) and serum hormone concentrations were measured before, in the middle and after the 8-week training period in 24 endurance trained males. Both groups improved significantly maximal treadmill velocity (Vmax) (p<0.001) and 3000 m running performance (HRVG; p<0.001 and PD; p=0.001). The relative changes in Vmax and countermovement jump were significantly greater in HRVG (p<0.05). Nocturnal heart rate decreased in both groups (p<0.01), but H…