Greater effects by performing a small number of eccentric contractions daily than a larger number of them once a week

Our previous study found that one maximal voluntary eccentric contraction (MVC-ECC) performed daily for 5 days a week for 4 weeks increased MVC-ECC, isometric (MVC-ISO), and concentric contraction (MVC-CON) torque of the elbow flexors more than 10%. The present study investigated the effects of six maximal voluntary eccentric contractions on the MVC torques and biceps brachii and brachialis muscle thickness (MT). Thirty-six healthy young adults were placed to one of the three groups (N = 12 per group); the 6 x 1 group that performed one set of six contractions once a week, the 6 x 5 group that performed one set of six contractions a day for 5 days a week, and the 30 x 1 group that performed five sets of six contractions a day in a week. The training duration was 4 weeks for all groups, and changes in MVC-ECC, MVC-CON and MVC-ISO torque, and MT before and after the 4-week training were compared among the groups. The 6 x 1 group did not show significant changes in muscle strength and MT. Significant (p < 0.05) increases in MVC-ECC (13.5 +/- 11.5%), MVC-ISO (9.3 +/- 5.5%), MVC-CON torque (11.1 +/- 7.4%) were evident for the 6 x 5 group only, and increases in MT were found for the 6 x 5 (10.4 +/- 4.4%) and 30 x 1 (8.0 +/- 5.8%) groups without a significant difference. These results suggest that performing a small number of eccentric contractions 5 days a week is more effective for increasing muscle strength than performing a larger volume of eccentric contractions once a week. However, it appears that training volume is a factor for muscle hypertrophy in a short-term training.

Automated summary

This study found that performing maximal voluntary eccentric contractions five days a week is more effective in increasing muscle strength than performing a larger volume of contractions once a week. It also showed that training volume affects muscle hypertrophy in the short-term.