Is practice rate rather than exercise intensity more important in health benefits of moderately obese postmenopausal women?

OBJECTIVE

The aim of this study was to evaluate the impact of brisk walking on physical fitness, body composition and fasting lipid-lipoprotein profile of women 50-65 years-old, once adherence or exercise intensity is considered.

METHODS

A sample of 159 healthy, sedentary, obese postmenopausal women (body mass index [BMI]=29-35 kg/m2) was subjected to 3 sessions/week of 45 min-walking, at 60% of heart rate reserve (HRR), during 16 weeks. Body composition, physical fitness and fasting lipid-lipoprotein profile were assessed before and after the intervention.

RESULTS

Among the three tertiles of adherence to exercise sessions (<71%, 71-87%,>87%) women displaying the greatest one were characterized by the highest reduction in body weight (-1.9±2.7 kg) (mean±SD), fat mass (-2.0±2.3 kg) and waist girth (-4.4±3.4 cm) and the best improvement in physical fitness (7.3±3.5 mL O2/kg/min), (P<0.0001). A comparable analysis based on tertiles of walking intensity (<56%, 56-63%,>63% HRR) did not show between-group differences in body composition or physical fitness. Also, the fasting lipid-lipoprotein profile was improved by a reduction of cholesterol, LDL cholesterol, and triglyceride levels and by an increase in HDL cholesterol, irrespective of the participants' adherence (0.05<P<0.0001).

CONCLUSIONS

A high practice rate seems to be the most important factor for physical fitness improvement and fat mass loss. Health benefits appear at 78 minutes of brisk walk per week and increase with adherence to training, in moderately obese and initially sedentary, postmenopausal women.