The benefits of strength training compared to endurance training on performance and metabolic parameters in dm 2

Introduction

One of the earliest recognizable defects in diabetes mellitus type 2 (DM 2) is likely to be located in the muscle tissue. It was our aim, therefore, to study the effects of a 4 month strength training (ST) program on muscle function, strength and cardiovascular endurance in the treatment of DM 2 and compare it to the benefits gained from aerobic endurance training (ET) in these patients. Additionally we investigated the effects of both strength and endurance training on serum lipids, blood pressure and glycaemic control.

Methods

Twenty-three DM 2 patients participated in a 4 month circuit-type resistance training program three times per week. ST was performed at stations and three sets per muscle group were performed in a series of 10-15 repetitions per set. As strength improved, the number of sets were increased by increments of 1 after 4, 8 and 12 weeks a final of 6 sets. A further, 17 DM 2 patients participated in a 4 month aerobic endurance exercise training program. This group trained three times a week (40-90min/week) on a cycle ergometer. Clinical and laboratory measurements were assessed at baseline and after training period for each group. Data analysis was performed using the Statistical Package for Social Sciences (SPSS 10.0). All parameters were described by mean values ± standard error of the means (SE). A student’s unpaired t-test was used to assess significant differences between groups at the same time and a paired student’s t-test was used to assess significant differences of the same variables within the group before and after training. Pearson product moment correlation coefficients were used to compare changes in LBM and % BF to the changes in metabolic parameters before and after ST. P values  0.05 were considered statistically significant.

Results

For ST group, glycosylated haemoglobin (HbA1C) declined from 8.3±1.7 mg/dl to 7.1±0.2, p=0.001, fasting blood glucose (BG) reduced from 204±16 to 147±8 mg/dl, p<0.001 and Insulin resistance (IR) improved, (p=0.04). A significant decrease in total cholesterol (TC) (207±8 vs.184±7 mg/dl, p<0.001) and triglyceride (TG) levels (229±25 vs.150±14 mg/dl, p=0.001) was also observed. Low-density lipoprotein cholesterol (LDL-C) decreased from 121±8 to 106±8 mg/dl, p=0.001, while high-density lipoprotein cholesterol (HDL-C) was significantly increased (43±2 vs. 48±2 mg/dl, p=0.004). In addition, significant improvements were found in lean body mass, muscle mass, percent body fat and absolute fat.

Conclusions

ST effectively improved maximum strength and muscle mass in DM 2 patients. The positive changes observed in the muscular system coincided with highly significant improvements in metabolic control that resulted in a decreased atherogenic lipid profile. ST was superior to ET in all metabolic parameters measured, except for blood pressure (BP). With the advantage of an improved lipid profile, ST may help to protect against the development of CVD in DM 2 patients. We therefore recommend that ST play a pivotal role in the treatment of DM 2.

References

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