Randomized Crossover Study of Effect of Resistance Training on Glycemic Control, Muscular Strength, and Cholesterol in Type I Diabetic Men

Abstract

The goal of this study was to evaluate a program of resistance weight training on cardiovascular risk factors, blood glucose management, and overallstrength in diabetic subjects. A randomized crossover design was performed on eight male type I (insulin-dependent) diabetic subjects (mean ± SD age 31 ± 3.5 yr, height 176 ± 5.6 cm, body wt 80 ± 15 kg, duration of diabetes 12.3 ± 9.8 yr, and insulin dose 24 U NPH/day and 21 U regular/day). The program consisted of heavy-resistance weight training 3 days/wk for 10 wk, concentrating on the strengthening of major muscle groups through progressive resistance. Blood tests included total cholesterol, triglycerides, very-low-density lipoprotein and high-densitylipoprotein cholesterol, and HbA_1c. These tests were repeated atthree time points during the program. Field-strength testing was performed before and after training. An improvement was seen in the squat (93.6% increase, P < 0.0001) and bench press (58% increase, P < 0.005). HbA_1c and triglyceride levels showed no change during the resting portion ofthe experiment but showed a significant change with the training program: HbA_1c 6.9 ± 1 . 4 vs. 5.8 ± 0.9% (P = 0.05) and triglyceride 5.044 ± 1.06 vs. 4.628 ± 0.88 mM (P = 0.01). Self-monitored glucose (taken pre- and postexercise) showed a decrease from 7.85 ± 3.13 to 7.05 ± 2.91 mM (P = 0.0001). Very-low-density lipoprotein cholesterol and triglycerides did not change after training. Analysis of variance showed no significant differences over time from the three time points with regard to reductions in cardiovascular risk factors or HbA_1c. Heavy-resistance strength training may be associated with a decrease inglycosylated hemoglobin and cholesterol in type I diabetic men after training, in addition to increasing overall strength.