Binge Drinking Following Resistance Exercise: Effect on Muscle Power Recovery

Alcohol impairs recovery of isokinetic performance following muscle damaging resistance exercise but no knowledge exists regarding alcohol’s effect on recovery of performance in explosive isotonic movements following resistance exercise that induces only limited muscle damage. Purpose: To investigate the effect of alcohol on recovery from resistance exercise for explosive performance measures. Methods: Nine healthy men (Mean ± SD: 24.8 ± 3.2 years, 176 ± 7 cm, 86.4 ± 14.6 kg) completed 2 identical acute heavy resistance exercise tests (AHRET) separated by 1 week. The AHRET consisted of 6 sets of 10 repetitions of smith machine squats at 80% of 1-repetition maximum (1-RM) with 2 min of rest between sets. From 10-20 minutes post-AHRET participants consumed either 190 proof grain alcohol (EtOH) equal to 1.086 g of alcohol per kg lean mass (82-122 ml total) or no alcohol (Placebo) diluted in an artificially sweetened and calorie free beverage. The participants were blinded to conditions and the order of conditions was counter-balanced. Blood alcohol concentration (BAC) was measured using a breathalyzer. Sixty-five minutes pre-exercise, participants ingested a meal replacement beverage (33.5 kJ per kg body mass). Before the AHRET (PRE) and the following morning (AM), participants performed three high pulls and three bench press throws with 30% of 1-RM, and 10 consecutive vertical jumps, all at maximal effort. Peak power was measured for all exercises. Muscle soreness was measured using analog scales at PRE and AM. Results: BAC peaked 60-90 min post-exercise in all participants (0.084 ± 0.017 g·dl-1) on alcohol ingestion days. No effect of alcohol was found for peak power in the high pull (EtOH, PRE: 1658 ± 432 W, AM: 1659 ± 260 W; Placebo, PRE: 1599 ± 397 W, AM: 1579 ± 301 W), bench press throw (EtOH, PRE: 1120 ± 276 W, AM: 1105 ± 295 W; Placebo, PRE: 1119 ± 202 W, AM: 1089 ± 257 W), or vertical jump (EtOH, PRE: 52.6 ± 13.5 W·kg-1, AM: 48.5 ± 6.3 W·kg-1; Placebo, PRE: 52.2 ± 9.4 W·kg-1, AM: 47.9 ± 9.0 W·kg-1). Leg soreness increased moderately from PRE to AM with no difference between conditions. CONCLUSION: A moderate BAC does not appear to affect explosive upper or lower body power capability on the morning following a heavy squat session that induces only limited muscle damage

Walking in high-heel shoes induces redistribution of joint power and work

ABSTRACTWalking in high-heel shoes (HHS) decreases the push-off power and little research has examined the specific muscle groups that compensate for it. The purpose was to examine the effects of walking in HHS compared to barefoot on lower extremity net joint work and power. Fourteen young women walked in HHS and barefoot at a fixed speed of 1.3 m·s−1. Marker position and ground reaction force data were synchronously measured at 100 and 1000 Hz, respectively. Peak power and joint work variables were computed over the power phases of the gait cycle using an inverse dynamic approach. When walking in HHS was compared to barefoot, participants exerted a diminished push-off characterized by lesser peak power and lesser work by the ankle plantar flexors in late stance (A2 phase; p < 0.001). To compensate for the reduced ankle plantar flexor power, greater peak power was generated and work was performed in early stance by hip extensors (H1 phase; p ≤ 0.001), in mid-stance by knee extensors (K2 phase; p < 0.001) and in late stance and early swing phase by hip flexor muscles (H3 phase; p ≤ 0.001). Walking in HHS induces biomechanical plasticity and causes distal-to-proximal redistribution of net joint power and work during walking

Creatine electrolyte supplement improves anaerobic power and strength: a randomized double-blind control study

Background Creatine supplementation aids the Phosphagen system by increasing the amount of free creatine and phosphocreatine available to replenish adenosine triphosphate. The purpose of this study was to investigate the effects of a creatine and electrolyte formulated multi-ingredient performance supplement (MIPS) on strength and power performance compared to a placebo. Maximal strength along with total concentric work, mean rate of force development (mRFD), mean power, peak power, and peak force for both bench press and back squat were determined at pre-test and post-test separated by 6 weeks of supplementation. Methods Twenty-two subjects (6 females, 21 ± 2 yrs., 72.46 ± 11.18 kg, 1.72 ± 0.09 m) performed a one-repetition maximum (1RM) for back squat and bench press. Eighty percent of the subject’s pre-test 1RM was used for a maximal repetition test to assess performance variables. Testing was separated by 6 weeks of supplementation of a MIPS dose per day in a double-blind fashion for comparison. A two-way mixed analysis of covariance (ANCOVA) was applied with an alpha level of 0.05. Results For their back squat 1RM, the MIPS group displayed significant increase of 13.4% (95% CI: 2.77, 23.8%) while placebo displayed a decrease of − 0.2% (95% CI: − 1.46, 2.87%) (p = 0.047, η p 2  = 0.201). The MIPS displayed a significant increase of 5.9% (95% CI: 2.5, 10.1%) and placebo displayed a non-significant increase of 0.7% (95% CI: − 3.49, 3.9%) in bench press maximal strength (p = 0.033,0.217). The MIPS group displayed a significant increase as well in total concentric work (26.5, 95% CI: 6.07, 46.87%, p = 0.008, η p 2  = 0.330) and mean power (17.9, 95% CI: 3.42, 32.46%, p = 0.003, η p 2  = 0.402) for the maximal repetition bench press test at 80% of their 1RM. Conclusions The MIPS was found to be beneficial to recreationally trained individuals compared to a placebo. The greatest benefits are seen in bench press and back squat maximal strength as well as multiple repetition tests to fatigue during the bench press exercise

Creatine-electrolyte supplementation improves repeated sprint cycling performance: A double blind randomized control study

Abstract Background Creatine supplementation is recommended as an ergogenic aid to improve repeated sprint cycling performance. Furthermore, creatine uptake is increased in the presence of electrolytes. Prior research examining the effect of a creatine-electrolyte (CE) supplement on repeated sprint cycling performance, however, did not show post-supplementation improvement. The purpose of this double blind randomized control study was to investigate the effect of a six-week CE supplementation intervention on overall and repeated peak and mean power output during repeated cycling sprints with recovery periods of 2 min between sprints. Methods Peak and mean power generated by 23 male recreational cyclists (CE group: n = 12; 24.0 ± 4.2 years; placebo (P) group: n = 11; 23.3 ± 3.1 years) were measured on a Velotron ergometer as they completed five 15-s cycling sprints, with 2 min of recovery between sprints, pre- and post-supplementation. Mixed-model ANOVAs were used for statistical analyses. Results A supplement-time interaction showed a 4% increase in overall peak power (pre: 734 ± 75 W; post: 765 ± 71 W; p = 0.040; ηp 2 = 0.187) and a 5% increase in overall mean power (pre: 586 ± 72 W; post: 615 ± 74 W; p = 0.019; ηp 2 = 0.234) from pre- to post-supplementation for the CE group. For the P group, no differences were observed in overall peak (pre: 768 ± 95 W; post: 772 ± 108 W; p = 0.735) and overall mean power (pre: 638 ± 77 W; post: 643 ± 92 W; p = 0.435) from pre- to post-testing. For repeated sprint analysis, peak (pre: 737 ± 88 W; post: 767 ± 92 W; p = 0.002; ηp 2 = 0.380) and mean (pre: 650 ± 92 W; post: 694 ± 87 W; p < 0.001; ηp 2 = 0.578) power output were significantly increased only in the first sprint effort in CE group from pre- to post-supplementation testing. For the P group, no differences were observed for repeated sprint performance. Conclusion A CE supplement improves overall and repeated short duration sprint cycling performance when sprints are interspersed with adequate recovery periods