Moderate Intensity Exercise Training Improves Cardiorespiratory Fitness in Women

Abstract

Among women, there is an increased prevalence of sedentary lifestyle and less participation in physical activity at levels recommended by the Surgeon General. As a result, women have been identified as a target group in public health initiatives to increase physical activity. The health-related benefits of habitual, moderate intensity physical activity are well documented in the epidemiological literature, but less is known about the effect of such physical activity on cardiorespiratory fitness. Our hypothesis was that moderate and vigorous exercise training regimens of similar estimated energy expenditure would result in similar changes in cardiorespiratory fitness. Eighteen sedentary premenopausal women with the following baseline characteristics [x w 6 SE]: maximal oxygen consumption (V Ç O 2 max) 5 29.5 6 1.5ml ? kg 2 1 ? min 2 1 ; age 5 33 6 1 years; height 5 162.6 6 0.9 cm; mass 5 62.7 6 2.3 kg, were randomly assigned to either vigorous (HI, 80% V Ç O 2 max, n 5 10) or moderate intensity (MOD, 40% V Ç O 2 max, n 5 8) cycle ergometer training groups. Exercise training was conducted 3-4 (3.37 6 0.05) days/week for 12 weeks in a supervised and progressive manner, with estimated exercise energy expenditure equated across both training groups. V Ç O 2 max and time to exhaustion increased significantly in both groups (p , 0.05), with no difference between groups. 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 between the groups in posttraining values. Women participating in moderate intensity exercise training as recommended in basic public health guidelines demonstrate an increase in cardiorespiratory fitness similar to that elicited by vigorous training. 65

Aerobic Fitness, Not Energy Expenditure, Influences Subsequent Increase in Adiposity in Black and White Children

“…We believe that VO 2max serves as a strong proxy indicator of habitual levels of moderate to vigorous physical activity, because this level of activity results in greater changes in VO 2max than do low intensity activities. 34,35 VO 2max is a more robust and less variable measure of physical activity than AEE for several reasons. First, VO 2max is less variable over time (CV Ͻ 10%; unpublished data), whereas AEE can vary greatly from day-to-day and week-to-week in the order of up to 60% (unpublished data).…”

Influence of Cardiopulmonary Exercise Testing Protocol and Resting VO2Assessment on %HRmax, %HRR, %VO2maxand %VO2R Relationships

“…In the early stages of a training program, for example, previously sedentary individuals have been shown to enhance cardiorespiratory fitness by training at exercise intensities as low as 40% VO2max [5]. However, the minimal intensity that enhances cardiorespiratory fitness is positively related to the cardiorespiratory fitness of the individual [39].…”

A Moderate-Intensity Exercise Program Fulfilling the American College of Sports Medicine Net Energy Expenditure Recommendation Improves Health Outcomes in Premenopausal Women

“…Second, exercise prescriptions designed according to % _ Vo 2 R (a net term), rather than % _ Vo 2 max (a gross term), can be directly calculated into net caloric expenditure. Despite the ACSM's shift in recommending the use of % _ Vo 2 R in place of % _ Vo 2 max, much of the research performed since the position stand has continued to prescribe exercise intensity according to % _ Vo 2 max (4,5,7,10,13,15). Most health and fitness organizations advocate a minimal volume of exercise that expends 1,000 kcalÁwk 21 at moderateintensity (20).…”

“…To our knowledge, there is no previous investigation that has examined the specific health outcomes associated with an exercise program fulfilling these requirements. The majority of previous research on energy expenditure reports the gross, rather than the net, caloric expenditure (4,5,7,14,15). Because the ACSM exercise prescription recommendations are the most recognizable guidelines for exercise professionals in fitness and rehabilitation settings, it is important to quantify the specific health benefits to be expected by following these guidelines.…”