Oxygen Consumption at 30？W of Exercise Is Surrogate for Peak Oxygen Consumption in Evaluation of Cardiorespiratory Fitness in Young-Adult African-American Females

Body mass index (BMI) is negatively correlated with cardiorespiratory fitness, measured by maximal or peak oxygen consumption ( ). measurements require heavy aerobic exercise to near exhaustion which increases the potential for adverse cardiovascular events. This study tests the hypothesis that measured at a fixed submaximal workload of 30？W is a surrogate for . We studied 42 normotensive African-American female university students, 18–25 years of age. We measured , blood pressure, and at a 30？W exercise workload and computed BMI. We found significant negative correlations between BMI and ( , ) and between BMI and at 30？W ( , ). Compared to , at 30？W increased the significance of the negative correlation with BMI. The heart rate-systolic pressure product at 30？W was positively correlated with BMI ( , ) and negatively correlated with ( , ). The positive correlation between BMI and the heart rate-systolic pressure product and the greater negative correlation between and BMI at 30？W of exercise than that at exercise to fatigue suggest that normalized measurements of at the fixed exercise workload of 30？W could be useful surrogates for measurements of . 1. Introduction Aerobic exercise testing provides valuable data for measuring a person’s cardiorespiratory fitness and overall health. Such testing is also a basis for developing individualized, safe exercise prescriptions. Maximal and peak oxygen consumption ( , ) are gold standard measuring cardiorespiratory fitness [1]. However, low cardiorespiratory fitness makes it difficult for sedentary, overweight, and/or obese individuals to complete the high-intensity protocols required for or determinations [2]. Moreover, such exercise may put individuals with low cardiorespiratory fitness at risk for adverse cardiovascular events because determinations of and require substantial exertion to near exhaustion or fatigue [3, 4]. These limitations are consistent with the report that positive electrocardiographic indicators of cardiovascular disease are only 75% sensitive in women, compared to 90% sensitive in men and that African-American women appear to exhibit lower than a matched population of Caucasian women [3]. These findings suggest that lack of reliable measures of cardiorespiratory fitness at submaximal workloads may limit our ability to evaluate the health status and prescribe appropriate exercise regimens for women. These impediments have been addressed by the usage of submaximal aerobic exercise tests that are shown to be equally as reliable as and for measuring cardiorespiratory fitness in sedentary