Search results for "Muscle strength"
showing 10 items of 428 documents
Muscle strength and muscle characteristics in monozygous and dizygous twins.
1979
Muscle strength and electrical activity were investigated on 31 pairs of young male and female monozygous (MZ) and dizygous (DZ) twins. The measurements included leg forces, force-time, running velocity, muscular power, maximal integrated electromyographic activity (IEMG) and chronaximetry of the quadriceps muscle group. In each parameter the intrapair variance was computed and the differences were tested between the MZ and DZ twins. The variance ratio (MZ vs. DZ) was statistically significant only for muscular power confirming an earlier finding which has demonstrated a genetic component for the variable. In addition to the various performance variables several key enzymes involved in ATP …
Serum hormones in soldiers after basic training: effect of added strength or endurance regimens.
2009
Introduction Military personnel are often exposed to training programs and operational situations that involve multiple stressors such as caloric deficit, sleep deprivation, and prolonged physical effort, which may disturb body homeostasis, as indicated by hormonal responses.Therefore, we investigated the effects of three training regimens on serum basal hormone concentrations before and after the 8-wk basic training (BT) period, and whether possible changes in serum basal concentrations are related to changes in endurance and strength performance. Methods Serum hormone levels were measured in 3 groups of 24 male military conscripts before and after 3 different types of training programs: n…
Age and Grip Strength Predict Hand Dexterity in Adults.
2015
In the scientific literature, there is much evidence of a relationship between age and dexterity,\ud where increased age is related to slower, less nimble and less smooth, less coordinated\ud and less controlled performances. While some suggest that the relationship is a direct consequence\ud of reduced muscle strength associated to increased age, there is a lack of research\ud that has systematically investigated the relationships between age, strength and\ud hand dexterity. Therefore, the aim of this study was to examine the associations between\ud age, grip strength and dexterity. 107 adults (range 18-93 years) completed a series of hand\ud dexterity tasks (i.e. steadiness, line tracking…
Effects of a 12-week strength training program on experimented fencers' movement time.
2014
The purpose of this study was to determine the effects of a 12-week strength training program on movement time (MT) on fencers of national level. Twelve male fencers were randomly divided into 2 groups: the control group (CG: N = 6; age, 22.3 ± 8.1 years) and the treatment group (TG: N = 6; age, 24.8 ± 7.2 years). The CG fencers followed the standard physical conditioning program, which was partially modified for the TG. The TG participated in a 12-week strength training program divided into 2 parts: maximal strength training, including weightlifting exercises (2 days a week for 6 weeks) and explosive strength training, with combined weights and plyometric exercises (2 days a week for 6 wee…
Effects of joint angle and age on ankle dorsi- and plantar-flexor strength.
2007
This study aimed at examining the effects of joint angle and age on the maximal voluntary contraction (MVC) torque, for the agonist and antagonist muscle groups around the ankle, i.e., the dorsi- and plantar-flexors. To this aim, neural and muscular factors were investigated in two groups of healthy men: 11 young (mean age, 24 years) and 18 older (mean age, 78 years). Plantar-flexion (PF) and dorsiflexion (DF) isometric MVC torques were measured in three different ankle joint angles and surface electromyographic activities of the triceps surae and of the tibialis anterior muscles were recorded. The main findings were that the DF-to-PF MVC torque ratio varied with joint angle and age, indica…
Effects of ageing on motor unit activation patterns and reflex sensitivity in dynamic movements.
2009
Both contraction type and ageing may cause changes in H-reflex excitability. H reflex is partly affected by presynaptic inhibition that may also be an important factor in the control of MU activation. The purpose of the study was to examine age related changes in H-reflex excitability and motor unit activation patterns in dynamic and in isometric contractions. Ten younger (YOUNG) and 13 elderly (OLD) males performed isometric (ISO), concentric (CON) and eccentric (ECC) plantarflexions with submaximal activation levels (20% and 40% of maximal soleus surface EMG). Intramuscular EMG data was analyzed utilizing an intramuscular spike amplitude frequency histogram method. Average H/M ratio was a…
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…
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…
Five years experience on 3,4-diaminopyridine phosphate in Lambert-Eaton syndrome: Case reports
2017
Abstract Rationale: To report our experience on 7 patients (4 males and 3 females), affected by nonparaneoplastic Lambert–Eaton myasthenic syndrome, treated with 3,4-diaminopyridine phosphate (3,4-DAPP) either alone or in combination with other immunosuppressants or steroids. Patient concerns: Patients have been evaluated at specific timepoints (ie, baseline and last 5 year follow-up), with neurological examination, autoantibodies against presynaptic voltage-gated Cav2.1 (P/Q type) calcium ion channel (VGCC) dosage, neurophysiological evaluation focusing on the increased amplitude of the compound muscle action potential (cMAP) after maximum voluntary effort, quantitative myasthenia gravis (…
Maximal Strength, Muscular Endurance and Inflammatory Biomarkers in Young Adult Men
2014
The aim was to study associations of maximal strength and muscular endurance with inflammatory biomarkers independent of cardiorespiratory fitness in those with and without abdominal obesity. 686 young healthy men participated (25±5 years). Maximal strength was measured via isometric testing using dynamo-meters to determine maximal strength index. Muscular endurance index consisted of push-ups, sit-ups and repeated squats. An indirect cycle ergometer test until exhaustion was used to estimate maximal aerobic capacity (VO2max). Participants were stratified according to those with (102 cm) and those without abdominal obesity (102 cm) based on waist circumference. Inflammatory factors (C-react…