KOFFLER, K. H., A. MENKES, R. A. REDMOND, W. E. WHITE-HEAD, R. E. PRATLEY, and B. F. HURLEY. Strength training accelerates gastrointestinal transit in middle-aged and older men. Med. Sci. Sports Exerc., Vol. 24, No. 2, pp. 415–419, 1992. Seven healthy, untrained men (age 60 ± 2 yr, JOURNAL/mespex/04.02/00005768-199204000-00004/ENTITY_OV0398/v/2017-07-20T222312Z/r/image-png ± SEM) were studied to determine the effects of a 13-wk total body strength training program on gastrointestinal transit time (GITT). Whole bowel transit time and mouth-to-cecum transit time were assessed before and after the training program. Subjects recorded dietary intake for the 5 d preceding their baseline GITT tests and repeated that diet for 5 d prior to their GITT tests after training. No significant changes in weight or JOURNAL/mespex/04.02/00005768-199204000-00004/ENTITY_OV0422/v/2017-07-20T222312Z/r/image-pngO2max were observed as a result of the training program. There was a small but significant decrease in body fat assessed by hydrodensitometry (23.4 ± 2.6% vs 21.8 ± 2.6%, P < 0.05). The training program resulted in a 41 ± 5% increase (P < 0.001) in upper body strength and a 45 ± 6% increase (P < 0.001) in lower body strength. A 38 ± 6% increase (P < 0.01) in peak torque of the knee extensors was also observed at 60 degrees · s-1. The training program significantly accelerated whole bowel transit time (41 ± 11 vs 20 ± 7 hr; P < 0.01). There was no significant change in mouth-to-cecum transit time. Thus, a strength training program can accelerate whole bowel transit time in previously sedentary middle-aged and older men. This effect appears to be in the large intestines.