Objective: To examine the effect of resistance training on insulin sensitivity in nonobese NIDDM patients.
Research design and methods: Previously sedentary nonobese NIDDM patients were enrolled in a resistance training group (RT; n = 9) or used as sedentary control subjects (SED; n = 8). SED subjects did not perform exercise training because of orthopedic disorders. The training program consisted of two sets of nine exercises with 10-20 repetitions. Subjects trained five times a week for 4-6 weeks. Insulin sensitivity, as assessed by the hyper-insulinemic-euglycemic clamp technique, HbAJc, and body composition, was measured before and after the training period. Maximal oxygen uptake (VO2max) and quadriceps strength were measured in the RT group.
Results: The two groups did not differ significantly on any variables before participation in the program. The glucose disposal rate during the hyperinsulinemic-euglycemic clamp increased 48% in the RT group (6.85 +/- 1.86 to 10.12 +/- 3.15 mg.kg-1 lean body mass.min-1; P < 0.05), but remained unchanged in the SED group (5.95 +/- 1.63 to 6.36 +/- 1.61 mg.kg-1 lean body mass.min-1). There was no significant change in body composition in either group. In the RT group, a 16% increase in quadriceps strength (191.1 +/- 45.8 to 216.9 +/- 42.8 Nm; P < 0.05) but no significant change (27.6 +/- 5.0 to 28.6 +/- 6.5 ml.kg-1.min-1) in VO2max was observed.
Conclusions: Moderate-intensity, high-volume resistance training improves insulin sensitivity in nonobese NIDDM without altering VO2max.