Effects of exercise intensity on physical fitness and risk factors for coronary heart disease

Objective: To determine whether "low-intensity" exercise (walking) and "high-intensity" exercise (aerobic dance), when added to a weight loss diet, have different effects on coronary heart disease (CHD) risk factors and physical fitness. Research Methods and Procedures: Ninety obese women were divided into diet only (DO), diet plus walking (DW), and diet plus aerobic dance (DA) groups. DXA was used to evaluate segmental body composition. Leg-extension strength and maximal oxygen uptake ((V) over dot O-2max) were the indicators of physical fitness. Blood pressure, lipoproteins, and fasting glucose were used as indices for CHD risk factors. These items were measured before and after a 14-week intervention period. Results: Whole-body plus all segmental fat masses were significantly reduced (p < 0.001). Reductions in whole-body and lower-limb fat- and bone-free masses were significantly less (p < 0.01) in the DA group (-1.5 and -0.1 kg, respectively) compared with the DO (-2.1 and -0.4 kg, respectively) and DW (-2.5 and -0.5 kg, respectively) groups. Improvements in leg-extension strength and (V) over dot O-2max were significantly greater (p < 0.05) in the DA group compared with the DO group. The CHD risk factors clearly improved (p < 0.05) within each group. Reductions in low density lipoprotein-cholesterol and fasting glucose were significantly greater (p < 0.05) in the DA group compared with the DO and DW groups. Discussion: Adding higher intensity aerobic dance to a weight-loss diet program may help maintain fat- and bone-free mass and may be more effective in improving CHD risk factors compared with low-intensity walking.