| Summary: | Estimation of human oxygen uptake (VO₂) during exercise is often used as an alternative when its direct measurement is not feasible. The American College of Sports Medicine (ACSM) suggests estimating human VO₂ during exercise on a cycle ergometer through an equation that considers individual’s body mass and external work rate, but not pedaling rate (PR). We hypothesized that including PR in the ACSM equation would improve its VO₂ prediction accuracy. Ten healthy male participants’ (age 19–48 years) were recruited and their steady-state VO₂ was recorded on a cycle ergometer for 16 combinations of external work rates (0, 50, 100, and 150 W) and PR (50, 70, 90, and 110 revolutions per minute). VO₂ was calculated by means of a new equation, and by the ACSM equation for comparison. Kinematic data were collected by means of an infrared 3-D motion analysis system in order to explore the mechanical determinants of VO₂. Including PR in the ACSM equation improved the accuracy for prediction of sub-maximal VO₂ during exercise (mean bias 1.9 vs. 3.3 mL O₂ kg⁻1 min⁻1 ) but it did not affect the accuracy for prediction of maximal VO₂ (P > 0.05). Confirming the validity of this new equation, the results were replicated for data reported in the literature in 51 participants. We conclude that PR is an important determinant of human VO₂ during cycling exercise, and it should be considered when predicting oxygen consumption.
|
|---|