Borst, S., De Hoyos, D., Lowenthal, D., Vincent, K., Garzarella, L., Pollock, B., & Pollock, M. (1998). Six months high- or low-volume resistance training increases circulating insulin-like growth factor. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 1556.

Since there are equivocal research findings concerning the relationship between physical activity and circulating insulin-like growth factor (IGF-I), this study attempted to determine the effects of resistance training on IGF-I and IGF binding protein (IGFBP-3). Ss (N = 11) participated in 25-week resistance training programs of low- (1 set) or high-volume (3 sets). Blood was sampled pre-, mid- (13 weeks), and post-training.

IGF-I increased similarly with both training intensities (34% low; 30% high). However, IGFBP-3 increased slightly but not significantly in both groups.

Implication. Resistance training increases IGF-I irrespective of training intensity. IGFBP-3 is unaffected by resistance training.

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