The effect of eccentric and concentric resistance training on quadriceps neuromuscular adaptations

The aim of this study was to investigate the effect of two types of eccentric and concentric training programs on neuromuscular adaptations of quadriceps muscle.

For this purpose, 24 subjects including non-athlete boys in the age range of 19 to 27 years in Bojnourd were randomly divided into two groups: eccentric (12 people) and concentric (12). The eccentric exercise group performed knee flexion with one leg at 150% 1RM to the limit of fatigue and the concentric exercise group performed knee extension with one leg at 75% 1RM to the limit of fatigue for 8 weeks. Surface electromyographic signals were measured and recorded before and after eight weeks of training for both groups. Multivariate analysis of variance (M-ANOVA) was used to examine changes in EMG variables before and after training sessions, muscle and training group as dependent variables.

Multivariate analysis of variance showed an increase in conduction velocity of action potential in both eccentric and concentric training groups after eight weeks of training. However, the rate of acceleration of the action potential in the quadriceps muscle of the eccentric group is significantly higher than the concentric group.

In general, the eccentric exercise group showed a greater increase in electromyographic indices compared to the concentric exercise group, which is probably related to the application of central nervous system mechanisms to eccentric contractions.