European journal of applied physiology
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Eur. J. Appl. Physiol. · Nov 2010
Performance and physiological responses to repeated-sprint and jump sequences.
In this study, the performance and selected physiological responses to team-sport specific repeated-sprint and jump sequence were investigated. On four occasions, 13 team-sport players (22 ± 3 year) performed alternatively six repeated maximal straight-line or shuttle-sprints interspersed with a jump ([RS(+j), 6 × 25 m] or [RSS(+j), 6 × (2 × 12.5 m)]) or not ([RS, 6 × 25 m] or [RSS, 6 × (2 × 12.5 m)]) within each recovery period. Mean running time, rate of perceived exertion (RPE), pulmonary oxygen uptake (V(O)₂), blood lactate ([La](b)), and vastus lateralis deoxygenation ([HHb]) were obtained for each condition. ⋯ Jumps increased RPE (Cohen's d ± 90% CL: +0.7 ± 0.5; 95% chance for RS(+j) > RS and +0.7 ± 0.5; 96% for RSS(+j) > RSS), V(O)₂(+0.4 ± 0.5; 80% for RS(+j) > RS and +0.5 ± 0.5; 86% for RSS(+j) > RSS), [La](b) (+0.5 ± 0.5; 59% for RS(+j) > RS and +0.2 ± 0.5; unclear for RSS(+j) > RSS), and [HHb] (+0.5 ± 0.5; 86% for RS(+j) > RS and +0.5 ± 0.5; 85% for RSS(+j) > RSS). To conclude, repeated- sprint and jump abilities could be considered as specific qualities. The addition of a jump within the recovery periods during repeated-sprint running sequences impairs sprinting performance and might be an effective training practice for eliciting both greater systemic and vastus lateralis physiological loads.
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Eur. J. Appl. Physiol. · Sep 2010
Randomized Controlled TrialEnhanced neural drive after maximal strength training in multiple sclerosis patients.
Multiple sclerosis (MS) patients suffer from impaired muscle activation and lower limb strength. Strength training enhances muscle activation and muscle strength, but neural adaptations to strength training remain unexplored in MS patients. The hypothesis was that maximal strength training (MST) using high loads and few repetitions would improve central neural drive and thus strength capacity of MS patients. 14 MS patients staying at a national MS rehabilitation center were randomly assigned to a MST group or a control group (CG). ⋯ MST group subjects were able to complete all training sessions. No adverse effects were reported. This randomized study provides evidence that MST is effective of augmenting the magnitude of efferent motor output of spinal motor neurons in MS patients, alleviating some neuromuscular symptoms linked to the disease.
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Eur. J. Appl. Physiol. · Sep 2010
Randomized Controlled TrialImmediate effects of acupuncture on strength performance: a randomized, controlled crossover trial.
The present study investigated the immediate efficacy of acupuncture compared to sham acupuncture and placebo laser acupuncture on strength performance. A total of 33 recreational athletes (25.2 +/- 2.8 years; 13 women) were randomized to receive acupuncture, sham acupuncture (needling at non-acupuncture points) and placebo laser acupuncture (deactivated laser device) in a double-blind crossover fashion with 1 week between trials. Assessment included bipedal drop jumps for maximum rebound height and quadriceps maximum isometric voluntary force (MIVF). ⋯ ANOVA did not show statistically significant treatment effects for drop jump height or MPF. The present study shows that a single acupuncture treatment was efficacious for improving isometric quadriceps strength in recreational athletes. These results might have implications not only for athletic performance enhancement, but also for rehabilitation programs aimed at restoring neuromuscular function.
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Eur. J. Appl. Physiol. · Sep 2010
Controlled Clinical TrialEffect of cycling on oxygenation of relaxed neck/shoulder muscles in women with and without chronic pain.
Work-related neck/shoulder muscle pain has been associated with increased anaerobic muscle metabolism. Thus, interventions to enhance oxygenation of painful muscles seem relevant. While cycling with relaxed shoulders has been shown to result in acute neck/shoulder muscle pain reduction, the effect on tissue oxygenation remains unknown. ⋯ Two min after termination of exercise, oxygenation was increased further in both groups, but significantly more in CON (8.8 microM) than in MYA (7.0 microM) (P = 0.05). In conclusion, cycling increases oxygenation of resting neck/shoulder muscles in women with and without trapezius myalgia, indicating acute positive effects of either neural or humoral factors on vascular beds of distant relaxed muscles. Although this beneficial response was observed in both groups, the post-exercise response was lower in women with trapezius myalgia.
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Eur. J. Appl. Physiol. · Jul 2010
Comparative StudyCold-induced vasoconstriction at forearm and hand skin sites: the effect of age.
During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. ⋯ E: -70 +/- 11 (n.s.)]. In conclusion, in contrast to results from the ventral forearm, elderly did not show a blunted response to local cooling and noradrenaline at hand skin sites. This indicates that at hand skin the noradrenergic mechanism of vasoconstriction is maintained with age.