The relative benefits of endurance and strength training on the metabolic factors and muscle function of people with type 2 diabetes mellitus

Abstract

Objective: To compare the effects of a 4-month strength training (ST) versus aerobic endurance training (ET) program on metabolic control, muscle strength, and cardiovascular endurance in subjects with type 2 diabetes mellitus (T2D).

Design: Randomized controlled trial.

Setting: Large public tertiary hospital.

Participants: Twenty-two T2D participants (11 men, 11 women; mean age +/- standard error, 56.2+/-1.1 y; diabetes duration, 8.8+/-3.5 y) were randomized into a 4-month ST program and 17 T2D participants (9 men, 8 women; mean age, 57.9+/-1.4 y; diabetes duration, 9.2+/-1.7 y) into a 4-month ET program.

Interventions: ST (up to 6 sets per muscle group per week) and ET (with an intensity of maximal oxygen consumption of 60% and a volume beginning at 15 min and advancing to a maximum of 30 min 3x/wk) for 4 months.

Main outcome measures: Laboratory tests included determinations of blood glucose, glycosylated hemoglobin (Hb A1c), insulin, and lipid assays.

Results: A significant decline in Hb A1c was only observed in the ST group (8.3%+/-1.7% to 7.1%+/-0.2%, P=.001). Blood glucose (204+/-16 mg/dL to 147+/-8 mg/dL, P<.001) and insulin resistance (9.11+/-1.51 to 7.15+/-1.15, P=.04) improved significantly in the ST group, whereas no significant changes were observed in the ET group. Baseline levels of total cholesterol (207+/-8 mg/dL to 184+/-7 mg/dL, P<.001), low-density lipoprotein cholesterol (120+/-8 mg/dL to 106+/-8 mg/dL, P=.001), and triglyceride levels (229+/-25 mg/dL to 150+/-15 mg/dL, P=.001) were significantly reduced and high-density lipoprotein cholesterol (43+/-3 mg/dL to 48+/-2 mg/dL, P=.004) was significantly increased in the ST group; in contrast, no such changes were seen in the ET group.

Conclusions: ST was more effective than ET in improving glycemic control. With the added advantage of an improved lipid profile, we conclude that ST may play an important role in the treatment of T2D.