Search results for "Muscle"
showing 10 items of 3397 documents
Relation between muscle mass, motor units and type of training in master athletes.
2014
OBJECTIVE: The aim of this study was to measure the number of motor units and muscle mass in power-trained and endurance-trained master athletes compared with community-dwelling older adults. METHODS: Seventy-five master athletes (52 power- and 23 endurance-trained athletes) were recruited at the 2012 European Veteran Athletics Championships in Zittau (Germany). One hundred and forty-nine community-dwelling older adults served as controls. In all participants, the motor unit number index (MUNIX) in the hypothenar muscle and whole body muscle mass was determined by bioelectrical impedance analysis (BIA). RESULTS: In both male and female master athletes, there were significant negative correl…
Effects of amino acids supplement on physiological adaptations to resistance training.
2009
KRAEMER, W. J., D. L. HATFIELD, J. S. VOLEK, M. S. FRAGALA, J. L. VINGREN, J. M. ANDERSON, B. A. SPIERING, G. A. THOMAS, J. Y. HO, E. E. QUANN, M. IZQUIERDO, K. HAKKINEN, and C. M. MARESH. Effects of Amino Acids Supplement on Physiological Adaptations to Resistance Training. Med. Sci. Sports Exerc., Vol. 41, No. 5, pp. 1111-1121, 2009. Introduction: Previous research has demonstrated that ingestion of essential amino acids and their metabolites induce anabolic effects with the potential to augment gains in lean body mass and strength after resistance exercise training. Purpose: The purpose of the present study was to examine the effects of an essential amino acid-based formula (Muscle Armor…
Changes in neuromuscular performance and muscle fiber characteristics of elite power athletes self-administering androgenic and anabolic steroids
1984
The influence of androgenic-anabolic steroid-induced changes in measures of body composition, muscle fiber characteristics and various aspects of the neuromuscular performance of the leg extensor muscles was investigated in five experimental and six control power athletes during the 24-week programmed strength training followed by the additional six week training without hormone drugs. The mean values of the dosages of self-administration during the 24-week period were 31.0 +/- 14.3 mg/day for anabolic steroids (methandienone, stanozolol, nandrolone) and 178.4 +/- 82.7 mg/week for testosterone. During the 24-week hormone period the experimental group gained in fat-free weight (p less than 0…
Acute hormonal responses to submaximal and maximal heavy resistance and explosive exercises in men and women.
2005
The purpose of this study was to examine acute hormonal and neuromuscular responses in men and women to 3 heavy resistance but clearly different exercise protocols: (a) submaximal heavy resistance exercise (SME), (b) maximal heavy resistance exercise (HRE), and (c) maximal explosive resistance exercise (EE). HRE included 5 sets of 10 repetition maximum (10RM) situps, bench press, and bilateral leg extensions (David 210 machine) with a 2-minute recovery between the sets. In SME, the load was 70%, and in EE, the load was 40% from that used in HRE. A significant increase (p , 0.05) in serum growth hormone (GH) was observed after HRE both in men and women, but the increase was greater (p < 0.05…
Muscle activation during cycling at different cadences: Effect of maximal strength capacity
2007
International audience; The purpose of this study was to examine the influence of maximal strength capacity on muscle activation, during cycling, at three selected cadences: a low cadence (50 rpm), a high cadence (110 rpm) and the freely chosen cadence (FCC). Two groups of trained cyclists were selected on the basis of the different maximal isokinetic voluntary contraction values (MVCi) of their lower extremity muscles as follow: Fmin (lower MVCi group) and Fmax (higher MVCi group). All subjects performed three 4-min cycling exercises at a power output corresponding to 80 % of the ventilatory threshold under the three cadences. Neuromuscular activity of vastus lateralis (VL), rectus femoris…
Isokinetic strength and anaerobic power of elite, subelite and amateur French soccer players.
2001
Information about the influence of different practice levels on physical characteristics of a large number of soccer players is lacking. Therefore we assessed muscular strength and anaerobic power of elite, subelite and amateur soccer players to clarify what parameters distinguish the top players from the less successful. We tested 95 soccer players from the French first division (elite), second division (subelite), and amateurs and determined the isokinetic strength of the knee extensor and flexor muscles at angular velocities from -120 degrees x s(-1) to 300 degrees x s(-1). Vertical jump, 10 m sprint, 30 m sprint and maximum ball speed during shooting were also measured. The elite player…
Explosive-strength training improves 5-km running time by improving running economy and muscle power
1999
To investigate the effects of simultaneous explosive-strength and endurance training on physical performance characteristics, 10 experimental (E) and 8 control (C) endurance athletes trained for 9 wk. The total training volume was kept the same in both groups, but 32% of training in E and 3% in C was replaced by explosive-type strength training. A 5-km time trial (5K), running economy (RE), maximal 20-m speed ( V 20 m), and 5-jump (5J) tests were measured on a track. Maximal anaerobic (MART) and aerobic treadmill running tests were used to determine maximal velocity in the MART ( V MART) and maximal oxygen uptake (V˙o 2 max). The 5K time, RE, and V MART improved ( P < 0.05) in E, but no…
Neuromuscular characteristics and fatigue in endurance and sprint athletes during a new anaerobic power test
1994
The purpose of this study was to investigate neuromuscular and energy performance characteristics of anaerobic power and capacity and the development of fatigue. Ten endurance and ten sprint athletes performed a new maximal anaerobic running power test (MARP), which consisted ofn x 20-s runs on a treadmill with 100-s recovery between the runs. Blood lactate concentration [la−]b was measured after each run to determine submaximal and maximal indices of anaerobic power (P 3mmol·1 −1,P5mmol·1 −1,P10mmol·1 −1andP max) which was expressed as the oxygen demand of the runs according to the American College of Sports Medicine equation: the oxygen uptake (ml·kg−1·min−1)=0.2·velocity (m·min−1) +0.9·s…
Endothelium-dependent component in the contractile responses of human omental arteries to adrenergic stimulation
1993
Abstract The present study was designed to investigate the influence of endothelium-derived nitric oxide on the contractile responses of isolated human omental arteries to electrical field stimulation and noradrenaline. We measured isometric tension in artery rings obtained from portions of human omentum during the course of abdominal operations (32 patients). Electrical field stimulation induced frequency-dependent contractions which were abolished by tetrodotoxin (10−6 M) and prazosin (10−6 M), thus indicating that this effect was due to noradrenaline released from adrenergic nerves acting on α1-adrenoceptors. The increases in tension induced by electrical field stimulation were of greate…
Central motor conduction time by magnetic stimulation of the cortex and peripheral nerve conduction follow-up studies in Friedreich's ataxia.
1998
A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9-12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for several years. Central motor conduction times were abnormal in all patients. Clinical conditions worsened significantly between successive examinations with significant increments in threshold and significant decrement of the amplitude of motor evoked potentials. The re…