Maximal oxygen uptake (VO2max) is the internationally recognized measure of a person's cardiorespiratory fitness. Currently the most accurate way of assessing one's true VO2max involves the use of maximal exercise tests, which require the use of specialized equipment, and are time consuming and costly. The purpose of this study was to determine the validity of the submaximal Siconolfi step test to estimate VO2max. A second purpose was to determine if body fat percentage improved the validity. Thirty-six individuals underwent a maximal treadmill test, in which VO2max was directly measured, and the step test. Results indicate that, although VO2max estimates generated by the Siconolfi step test are highly correlated to true VO2max (r =.887; p<.01), the values consistently underestimated a person's aerobic fitness. It was also determined that body fat percentage did not contribute to the prediction of VO2max.

The determination of adiposity in adolescents is often assessed with calculations of body mass indices (BMI). Researchers often obtain these measurements from self-reported (SR) values. The purpose of this study was to determine the accuracy of SR height, weight, and calculated BMI (from height and weight). SR and actual measured (ME) BMI values were compared with standards from the FITNESSGRAM® Healthy Fitness Zone (HFZ) classifications. SR height and calculated BMI were found to be accurate while SR weight was, on average, underreported by 4.77 lbs. Because of these errors in SR height and weight, accuracy of classification into the FITNESSGRAM® HFZ was compromised. Consequently, it is important that researchers ascertain actual values of height and weight when measuring adolescents rather than use those from self-reports.