Benefits of moderate-intensity exercise during a calorie-restricted low-fat diet

Abstract

Objective: Despite the health benefits, many people do not undertake regular exercise. This study investigated the effects of moderate-intensity exercise on cardiorespiratory fitness (lung age, blood pressure and maximal aerobic power, VO2max), serum lipids concentration and body mass index (BMI) in sedentary overweight/obese adults consuming a calorie-restricted low-fat diet. Design: Randomized diet and exercise intervention. Setting: Lincolnshire, UK. Methods: Sixty overweight/obese (BMI ≥ 25kgm−2) adults were randomized to either a calorie restricted low-fat diet (20 per cent of total energy as fat) or the same diet with the addition of moderate-intensity physical exercise (30 minutes, twice a week) for eight weeks; 20 completed the study. Participants’ serum lipids concentrations, BMI, blood pressure, resting pulse rate, VO2max and lung age were measured before the start of the intervention and during the fourth and eighth weeks. Results: Reductions in blood pressure (10 per cent versus 1 per cent), pulse rate (13 per cent versus 8 per cent) and weight (5 per cent versus 2 per cent) were greatest for the diet with exercise group. Exercise resulted in a significant ( p ≤ 0.05) increase in average VO2max (by 17 per cent) and reduction in average lung age by about 19 years. Further, reduction in participants’ lung age ranged from 1 to 37 years. However, there was no significant difference in BMI, blood pressure and serum lipids concentration between groups. Conclusion: Although exercise on most days of the week would result in maximum health benefits, 30 minutes of moderate-intensity exercise twice a week could significantly improve cardiorespiratory fitness (blood pressure and lung age) and the risk of cardiovascular diseases in previously sedentary overweight/obese adults.