Effect of aerobic exercise on insulin resistance and central adiposity disappeared after the discontinuation of intervention in overweight women.

PURPOSE

This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance (HOMA-IR) are maintained after discontinuation of intervention in the overweight/obese (OWOB) women.

METHODS

The study subjects were from 2 independent studies with similar aerobic exercise (AE) intervention programs. In study I, 15 OWOB postmenopausal women with pre-diabetes (body mass index, BMI = 24-33 kg/m, aged 52-65 years) completed an 8-month exercise intervention and were followed for 2 years after the intervention. In study II, 12 OWOB (BMI = 25-35 kg/m, aged 30-50 years) premenopausal women participated in a 6-week AE and were followed for 4 years after the intervention. The exercise program consisted of progressive AE with intensity of 60%-75% of initial fitness level, 30-60 min/time and 3-5 times/week. Fat mass (FM) was assessed by Dual Energy X-ray Absorptiometry (DXA Prodigy; study I) or bioelectrical impedance device (Inbody 720; study II). Plasma glucose and insulin were assessed by chemiluminescent immunoassay and HOMA-IR was calculated.

RESULTS

Both 8-month and 6-week moderate AE were effective in reducing HOMA-IR (-18.9%,  = 0.012 and -26.7%,  = 0.046, respectively), and 8-month AE reduced FM at upper abdominal region (-6.2%,  = 0.021). However, these improvements were not maintained in either study at the follow-up.

CONCLUSION

The AE program used in these studies was effective to reduce insulin resistance and/or FM in central body region among overweight and obese women. However, when exercise intervention was discontinued, the beneficial effects following both short- and long-term intervention disappeared. Thus maintaining exercise seems to be required if one wants to reap the benefits of exercise in the long-term.