GENDER DIFFERENCES IN STRENGTH GAIN FOLLOWING A RESISTANCE TRAINING PROGRAM IN THE UPPER ARM

Abstract

Resistance training for the purpose of promoting strength is an important component of one's overall fitness. The development of strength is beneficial for both sexes, especially as one ages and naturally begins to lose muscle mass. Strength gains have been observed in both sexes following resistance training, however very little is known in regards to patterns of strength gains between gender. PURPOSE To assess differences in strength between sexes in the dominant (D) and non-dominant (ND) arm, following a 12 week ND arm training program. METHODS Subjects between 18–39 years old participated in a 12 week training program. Subjects trained only their ND upper arm with five different exercises that utilized the bicep and tricep muscle groups. Bicep strength was measured in both arms by completing a one repetition maximum (1 RM) preacher bench curl, pre-post training. In addition, an upper arm circumference measure was completed pre-and post training. RESULTS 132 females and 85 males (25.2±6.2 and 24.4±5.1 years old, respectively) participated in the study. In females ND and D arm, an increase (p < .001 and p < .01, respectively) in strength was observed pre-post training in the 1RM (34% and 11%, respectively). In males, the ND arm observed an increase (p < .001) in strength pre-post training in the 1RM (27%). No difference in strength was observed in the males D arm. Females and males ND arm circumference increased (p < .01) pre-post training (5% and 7%, respectively). No differences were observed in the D arm circumference in either sex. In comparing gender, the % change in females 1 RM pre-post training was greater in the ND and D arm (p < .0001 and p < .01, respectively). No gender pre-post training % differences were observed with arm circumference. CONCLUSION Females observed a greater % increase in strength, as compared to males in the ND. In addition, the D arm in females observed a greater % increase in strength as compared to males, suggesting a greater cross over effect. However, the strength gain differences between sexes did not support similar morphological changes in arm circumference, reinforcing that neural factors initially may be more important. Supported by NINDS Grant R01 NS40606