Search results for "exercise physiology"
showing 10 items of 185 documents
Muscle cross-sectional area and voluntary force production characteristics in elite strength- and endurance-trained athletes and sprinters
1989
Seven male elite strength-trained athletes (SA) from different weight categories, six elite sprinters (SPA) and seven elite endurance-trained athletes (EA) volunteered as subjects for examination of their muscle cross-sectional area (CSA), maximal voluntary isometric force, force-time and relaxation-time characteristics of the leg extensor muscles. The SA group demonstrated slightly greater CSA and maximal absolute strength than the SPA group, while the EA group demonstrated the smallest values both in CSA and especially in maximal strength (p<0.05). When the maximal forces were related to CSA of the muscles, the mean value for the SA group of 60.8±10.0 N·cm−2 remained slightly greater than…
Influence of Scapular Position on the Core Musculature Activation in the Prone Plank Exercise
2017
Cortell-Tormo, JM, García-Jaén, M, Chulvi-Medrano, I, Hernández-Sánchez, S, Lucas-Cuevas, ÁG, and Tortosa-Martínez, J. Influence of scapular position on the core musculature activation in the prone plank exercise. J Strength Cond Res 31(8): 2255-2262, 2017-Prone plank is a widely used exercise in core stability training. Research has shown that pelvic tilt plays an important role on the electromyographic (EMG) activation of core musculature. However, the influence of scapular position on EMG activation is currently unknown. Therefore, this study evaluated the influence of scapular position on the core muscles during a prone plank. Surface EMG of the rectus abdominis (RA), external oblique (…
Effects of long-term training specificity on maximal strength and power of the upper and lower extremities in athletes from different sports
2002
Maximal concentric one repetition maximum half-squat (1RM(HS)), bench-press (1RM(BP)), power-load curves during concentric actions with loads ranging from 30% to 100% of 1RM(HS) and 1RM(BP)were examined in 70 male subjects divided into five groups: weightlifters (WL, n=11), handball players (HP, n=19), amateur road cyclists (RC, n=18), middle-distance runners (MDR, n=10) and age-matched control subjects (C, n=12). The 1RM(HS)values in WL, HP and RC were 50%, 29% and 28% greater, respectively, ( P<0.001-0.01) than those recorded for MDR and C. The half-squat average power outputs at all loads examined (from 30% to 100%) in WL and HP ( P<0.001 at 45% and 60% with HP) were higher ( P<0.05-0.00…
Influence of load and stretch shortening cycle on the kinematics, kinetics and muscle activation that occurs during explosive upper-body movements.
1997
Although explosive power in lower-body movements has been extensively studied, there is a paucity of research examining such movements in the upper body. This study aimed to investigate the influence of load and the stretch shortening cycle (SSC) on the kinematics, kinetics, and muscle activation that occurs during maximal effort throws. A total of 17 male subjects performed SSC and concentric only (CO) bench throws using loads of 15%, 30%, 45%, 60%, 75%, 90% and 100% of their previously determined one repetition maximum bench press. The displacement, velocity, acceleration, force and power output as well as the electromyogram (EMG) from pectoralis major, anterior deltoid, and triceps brach…
The effect of lifelong exercise on psychomotor reaction time: a study of 38 pairs of male monozygotic twins
1998
Purpose: The aim was to study the effect of lifetime physical activity on psychomotor speed. Methods: Foot and dominant hand visual simple and choice psychomotor reaction times were studied among monozygotic twins (38 pairs) aged 35-69, discordant for lifetime exercise histories. Results: There was a trend that some components of psychomotor reaction time were faster for frequent than for occasional exercisers. but the findings were not consistent for the hand and feet. After controlling for occupational physical activity, only choice decision time for the hand (26 ms, P < 0.01) and choice reaction time for the contralateral foot (51 ms, P < 0.05) both remained 7% faster. There was no trend…
Stretch shortening cycle fatigue: interactions among joint stiness, reflex, and muscle mechanical performance in the drop jump
1996
The purpose of the present study was to investigate the effect of strenuous stretch-shortening cycle exercise on the relationship between reflex and stiffness regulation during the drop jump. Ten healthy male subjects performed submaximal stretch-shortening cycle exercise on a special sledge apparatus. Exhaustion occurred on average within 3 min. A drop jump test from a 50-cm height was performed immediately before and after the sledge exercise, as well as 2 h, 2 days and 4 days later. The fatigue exercise showed relatively high blood lactate concentrations 12.5 (SD 2.6) mmol·l−1 and a 2-day delayed increase of serum cretaine kinase concentration. In drop jumps, the short latency M1 compone…
Effects of differently induced stretch loads on neuromuscular control in drop jump exercise
1996
The neuromuscular characteristics of the triceps surae and vastus lateralis muscles and interactions between the pre-activation of these muscles and the muscle output itself during ground contact were investigated during various types of stretch-shortening cycle muscle loading. The loading of the muscles was effected by using three different types of drop jump exercise. These jumps allowed separate modifications of the loading of the leg extensor muscles by changing the velocity of the centre of gravity (CG) or by changing directly the body mass, which was also affected by changing artificially the acceleration of the CG. It was found that the eccentric peak angular velocity of the ankle jo…
Reduced stretch-reflex sensitivity after exhausting stretch-shortening cycle exercise.
1996
The stretch-shortening cycle (SSC) is an effective and natural form of muscle function but, when repeated with sufficient intensity or duration, it may lead to muscle damage and functional defects. A reduced tolerance to impact has been reported, which may be partly attributed to a reduced stretch-reflex potentiation. The aim of the present study was to examine the influence of SSC-induced metabolic fatigue and muscle damage on the efficacy of stretch reflexes, as judged by the electromyograph (EMG) response of two shank muscles (lateral gastrocnemius LG, soleus SOL) to controlled ramp stretches. These EMG responses were recorded before and immediately after exhausting SSC-type leg exercise…
Effects of Water Immersion Methods on Postexercise Recovery of Physical and Mental Performance.
2019
Ahokas, EK, Ihalainen, JK, Kyrolainen, H, and Mero, AA. Effects of water immersion methods on postexercise recovery of physical and mental performance. J Strength Cond Res 33(6): 1488-1495, 2019-The aim of this study was to compare the effectiveness of 3 water immersion interventions performed after active recovery compared with active recovery only on physical and mental performance measures and physiological responses. The subjects were physically active men (age 20-35 years, mean ± SD 26 ± 3.7 years). All subjects performed a short-term exercise protocol, including maximal jumps and sprinting. Four different recovery methods (10 minutes) were used in random order: cold water immersion (C…
Does a Mental Training Session Induce Neuromuscular Fatigue?
2014
ROZAND, V., F. LEBON, C. PAPAXANTHIS, and R. LEPERS. Does a Mental Training Session Induce Neuromuscular Fatigue? Med. Sci. Sports Exerc., Vol. 46, No. 10, pp. 1981–1989, 2014. Mental training, as physical training, enhances muscle strength. Whereas the repetition of maximal voluntary contractions (MVC) induces neuromuscular fatigue, the effect of maximal imagined contractions (MIC) on neuromuscular fatigue remains unknown. Here, we investigated neuromuscular alterations after a mental training session including MIC, a physical training session including MVC, and a combined training session including both MIC and MVC of the elbow flexor muscles. Methods: Ten participants performed 80 MIC (d…