Muscular Strength and Endurance Responses to Eccentric-Enhanced Resistance TVaining

Traditional (TRAD) resistance training involves equal loading during the concentric and eccentric phases. Whereas eccentric-enhanced (ECC+) resistance training involves concentric and overloaded eccentric muscle actions, and purportedly results in greater muscle strength and mass than TRAD. PURPOSE: To test the hypothesis that ECC+ would result in greater muscle performance outcomes than TRAD after a five-week progressive resistance training program. METHODS: Twenty-two previously untrained males (22.1 ± 0.8 yrs) were randomized into training volume matched TRAD (4 sets × 6 reps at 52.5% 1RM) or ECC+ (3 sets × 6 reps at 40% 1RM concentric and 100% 1RM eccentric) groups. Participants performed chest press and squat exercise (3 × week-1) for five weeks. Training loads were increased for subsequent sessions upon successful completion of assigned repetitions. Chest and leg muscle strength [one repetition maximum (1RM)] and endurance (repetitions to fatigue) were assessed before and after the intervention. RESULTS: Muscle performance measures were similar between groups at baseline. Following the intervention, chest press (+10.1 % TRAD; +9.0% ECC+) and squat (+25.4% TRAD; +18.6% ECC+) muscle strength and chest press (+8.9% TRAD; +9.1% ECC+) and squat (+21.7% TRAD; +19.4% ECC+) endurance increased similarly between groups, respectively. Although matched at the onset of training, the total training volume over five-weeks was greater in the TRAD than the ECC+ group (83037 ± 4082 kg vs. 72458 ± 3164 kg, p<0.05), respectively. CONCLUSIONS: ECC+ may be a more efficient mode of training than TRAD, as muscle performance responses were similar between groups despite a lower total training volume in the ECC+ group.