EFFECTS OF CONCENTRIC AND ECCENTRIC HAMSTRING STRENGTH TRAINING ON 1-RM VALUES IN HEALTHY ADULT MALES

Abstract

1094 Previous research has suggested that eccentric hamstring strength training resulted in greater improvements in 1-RM values than concentric training for males. The present study examined the effects of concentric and eccentric hamstring strength training on 1-RM values for healthy adult males (N = 22, age = 29.17 ±4.12; wt = 173.5 ±26.47 lbs; ht = 70.49±2.48) randomly assigned to either concentric or eccentric training groups. Participants were involved in a 12-week training protocol three days per week. Hamstring training was performed using the NEGATOR™ (Myotonic Corporation, Metairie, LA) isotonic weight training device which can produce concentric and eccentric muscle leading. All participants performed 3 sets of 8 repetitions at 70% 1-RM concentrically. The eccentric group performed an additional 10%-100% above 1-RM eccentrically. Changes were monitored by completing a 1-RM test protocol at 0-wks, 3-wks, 9-wks, and 12-wks of training. Results of a group (Eccentric, Concentric) × Time repeated measures ANOVA indicated a non-significant interaction (p = .108, ηsquared = .095). The time main effect was significant (p < .0001, ηsquared = .818). One degree-of-freedom simple contrasts indicated a progressive increase in 1-RM values across the 12-week training period. This suggests that hamstring training is effective for developing hamstring muscle strength. Contrary to previous research, eccentric hamstring training did not produce greater improvements in concentric 1-RM values than concentric training.