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The purpose of the study was to determine if cycling exercise combined with (–)-epicatechin supplementation was more effective at increasing training adaptations than cycling combined with a placebo. Blood and muscle samples were obtained at rest before and after training to determine the effects of (–)-epicatechin supplementation on total serum antioxidant capacity, skeletal muscle mitochondrial protein content, and skeletal muscle myostatin gene expression. Participants (n = 20) completed two testing sessions separated by 4 weeks of cycle training, with supplementation of 100 mg (200 mg total daily) of (–)-epicatechin or a placebo, twice daily. Data were analyzed using a two-way mixed model ANOVA for each variable and the alpha level was set at p ≤ 0.05. A significant increase was observed for time for relative peak anaerobic power (p < 0.01), relative anaerobic capacity (p < 0.01), and fatigue index (p < 0.01). A significant increase was observed for time for absolute peak VO2 (p < 0.01) and peak power output obtained during the peak VO2 test (p < 0.01). A significant interaction between group and time for relative peak VO2 was observed (p = 0.04). Relative peak VO2 significantly increased over time in the placebo group (p < 0.01), but not in the (–)-epicatechin group (p = 0.21). A significant increase was observed for time for total serum antioxidant capacity (p = 0.01). No interaction or main effect of time was observed for myostatin (p > 0.05). Likewise, no interaction or main effect of time was observed for cytochrome C or citrate synthase (p > 0.05). A significant interaction effect was observed for succinate dehydrogenase (SDH; p = 0.02). SDH content increased significantly for the placebo group (p = 0.03, partial η2 = 0.59), but not for the (–)-epicatechin group (p = 0.81). Further, whereas no difference existed between the groups for SDH at baseline (p = 0.23), SDH content was significantly greater in the placebo group at the post time point (p = 0.01). Results indicate that (–)-epicatechin supplementation does not affect myostatin gene expression or anaerobic training adaptations but inhibits aerobic and mitochondrial SDH adaptations to cycle exercise training.

The purpose of this study was to examine differences between a free-weight squat (FWS) and machine squat (MS) during an initial resistance training phase for augmentation of performance tests in recreationally active women. Twenty-seven women (22.7 ± 3.5 years) were block-randomized to three groups: FWS, MS, or control (CON) and completed pre- and post-testing sessions consisting of the squat one-repetition maximum (1-RM), vertical jump, pro-agility test, zig-zag change-of-direction (COD) test, and 30-meter sprint. Participants trained two sessions per week for six weeks by performing jumping, sprinting, and COD drills followed by FWS, MS, or no squats (CON). Peak jump power increased for CON (p = 0.03) and MS (p < 0.01) groups. Change in peak jump power was greater for the MS group compared with the FWS group (p = 0.05). Average jump power increased for the MS group (p < 0.01). Change in average jump power was greater for the MS group compared with the CON group (p = 0.04). Vertical jump height, pro-agility, 30-meter sprint, and zig-zag COD tests improved over time (p < 0.01), with no difference between groups (p > 0.05). Machine squat training maximized jumping power compared with FWS training and CON. Both resistance training groups and the CON group improved equally in the pro-agility, 30-meter sprint, and zig-zag COD tests. Machine squat training may provide performance-enhancing benefits of equal or superior value to those obtained with free-weight squat training in recreationally active women during an initial training mesocycle. These findings also stress the importance of task-specific training in this population of untrained women, as the control group improved in terms of performance to the same degree as both resistance training groups.

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