EFFECTS OF RESISTANCE EXERCISE ON GLUCOSE-TOLERANCE IN NORMAL AND GLUCOSE-INTOLERANT SUBJECTS

This study was conducted to determine whether improvements in glucose tolerance could be observed after a single bout of resistance exercise in young (27.1 +/- 1.24 yr) control subjects, older (53.3 +/- 1.7 yr) patients with non-insulin-dependent diabetes mellitus (NIDDM), and ol der (50.7 +/- 1.9 yr) age-matched control subjects. Each subject was s creened for fitness level and any contraindications to exercise before inclusion in the study. A 75-g oral glucose tolerance test was admini stered 2 wk after the subjects were screened, and the subjects were fa miliarized with the exercise equipment. The maximum weight that could be lifted with one repetition was determined on seven Nautilus machine s that utilized the upper and lower body. After a 48-h rest period, a S-set X 10-repetition protocol based on the subject's one repetition m aximum was completed by each participant on each machine. Eighteen hou rs after the lifting protocol, a second oral glucose tolerance test, w as administered. There was no change in the pre- to postexercise gluco se levels in any of the treatment groups, but the total insulin respon ses (area under the curve) of the young control and NIDDM groups were significantly lower after exercise: from 6.93 +/- 0.8 X 10(3) to 5.38 +/- 0.65 x 10(3) pM in the young control group and from 9.83 +/- 1.95 X 10(3) to 7.77 +/- 1.50 X 10(3) pM in the NIDDM group. The postexerci se C-peptide levels were unchanged in all groups. The decrease in insu lin 18 h after exercise in the young control and NIDDM groups, with no change in insulin secretion (C-peptide data), indicates an enhanced a bility to clear insulin from the blood. Whether the removal is periphe ral and/or hepatic cannot be determined from these data, but the resul ts show that resistance exercise can influence insulin action without affecting glucose tolerance.