Moderate intensity exercise training improves cardiorespiratory fitness inwomen

Among women, there is an increased prevalence of sedentary lifestyle and le ss participation in physical activity at levels recommended by the Surgeon General. As a result, women have been identified as a target group in publi c health initiatives to increase physical activity. The health-related bene fits of habitual, moderate intensity physical activity are well documented in the epidemiological literature, but less is known about the effect of su ch physical activity on cardiorespiratory fitness. Our hypothesis was that moderate and vigorous exercise training regimens of similar estimated energ y expenditure would result in similar changes in cardiorespiratory fitness. Eighteen sedentary premenopausal women with the following baseline charact eristics [x +/- SE]: maximal oxygen consumption ((V) over dot O(2)max) = 29 .5 +/- 1.5ml.kg(-1). min(-1); age = 33 +/- 1 years; height 162.6 +/- 0.9 cm ; mass = 62.7 +/- 2.3 kg, were randomly assigned to either vigorous (HI, 80 % ((V) over dot O(2)max, n = 10) or moderate intensity (MOD, 40% ((V) over dot)O(2)max), n = 8) cycle ergometer training groups. Exercise training was conducted 3-4 (3.37 +/- 0.05) days/week for 12 weeks in a supervised and p rogressive manner, with estimated exercise energy expenditure equated acros s both training groups, ((V) over dot O(2)max) and time to exhaustion incre ased significantly in both groups (p < 0.05), with no difference between gr oups. Both groups had lower (p < 0.05) posttraining submaximal heart rates (HR), respiratory exchange ratios (RER), and ratings of perceived exertion (RPE) during graded exercise testing, with no significant differences betwe en the groups in posttraining values. Women participating in moderate inten sity exercise training as recommended in basic public health guidelines dem onstrate an increase in cardiorespiratory fitness similar to that elicited by vigorous training.