RESUMEN
The purposes of this study were to clarify the electromyography (EMG) of plantar flexors and to analyze the fascicle and tendon behaviors of the gastrocnemius medialis (GM) during running in the carbon-fiber plate embedded in thicker midsole racing shoes, such as the Nike ZoomX Vaporfly (VF) and traditional racing shoes (TRAD). We compared the fascicle and series elastic element behavior of the GM and EMG of the lower limb muscles during running (14 km/h, 45 s) in athletes wearing VF or TRAD. GM EMGs in the push-off phase were approximately 50% lower in athletes wearing VF than in TRAD. Although the series elastic element behavior and/or mean fascicle-shortening velocity during the entire stance phase were not significantly different between VF and TRAD, a significant difference was found in both the mean EMG and integral EMG of the GM during the push-off phase. EMG of the gastrocnemius lateralis (GL) during the first half of the push-off phase was significantly different between VF and TRAD. Present results suggest that VF facilitates running propulsion, resulting in a decrease in GM and GL EMGs at a given running velocity during the push-off phase, leading to a reduction in metabolic cost.
Asunto(s)
Fibra de Carbono , Electromiografía , Músculo Esquelético , Carrera , Zapatos , Humanos , Músculo Esquelético/fisiología , Carrera/fisiología , Masculino , Adulto , Adulto Joven , Fenómenos BiomecánicosRESUMEN
Background: Coenzyme Q10 (CoQ10) is the electron transporter in oxidative phosphorylation and an endogenous antioxidant. Recent researches have indicated that doses of 200-300 mg/day are needed to recognize effects to prevent oxidative damage in athletes, and the reduced form of CoQ10, ubiquinol-10, is more bioavailable than its oxidized form. Therefore, we hypothesized that higher doses of ubiquinol-10 could elevate plasma CoQ10 levels rapidly and exert physiological benefits in athletes. Therefore, a placebo controlled, double blinded test was carried out to determine the effects of ubiquinol-10 on the extravasate enzymes and fatigue levels of distance runners. Methods: Sixteen male collegiate distance runners were allocated to two groups receiving 300 mg/day of ubiquinol-10 (19.8 ± 1.7 years) or a placebo (20.1 ± 1.6 years) for 12 days during summer training that comprised 25- and 40-km runs on days 7 and 9, respectively. Results: Ubiquinol-10 elevated plasma CoQ10 concentration to 5.62 µg/mL and significantly decreased activities of the serum extravasate enzymes, CK, ALT, LDH (P < 0.01), and AST (P < 0.05) on day 6. Subjective fatigue status was significantly elevated on day 10 (the day after the 45-km run) in the placebo group (P < 0.001), but did not significantly change in the group given ubiquinol-10. Therefore, ubiquinol-10 could mitigate tissue damage and alleviate fatigue status in distance runners during summer training. Conclusions: Ubiquinol-10 (300 mg/day) supplementation elevated plasma CoQ10 concentrations almost to plateau levels, decreased extravasate enzymes within six days, and suppressed the subjective fatigue in male distance runners.