Validation of a New Method for Estimating VO2max Based on VO2 Reserve

Purpose: The American College of Sports Medicine\u27s (ACSM) preferred method for estimating maximal oxygen consumption (V̇O2max) has been shown to overestimate V̇O2max, possibly due to the short length of the cycle ergometry stages. This study validates a new method that uses a final 6-min stage and that estimates V̇O2max from the relationship between heart rate reserve (HRR) and V̇O2 reserve. Methods: A cycle ergometry protocol was designed to elicit 65–75% HRR in the fifth and sixth minutes of the final stage. Maximal workload was estimated by dividing the workload of the final stage by %HRR. V̇O2max was then estimated using the ACSM metabolic equation for cycling. After the 6-min stage was completed, an incremental test to maximal effort was used to measure actual V̇O2max. Forty-nine subjects completed a pilot study using one protocol to reach the 6-min stage, and 50 additional subjects completed a modified protocol. Results: The pilot study obtained a valid estimate of V̇O2max (r = 0.91, SEE = 3.4 mL·min−1·kg−1) with no over- or underestimation (mean estimated V̇O2max = 35.3 mL·min−1·kg−1, mean measured V̇O2max = 36.1 mL·min−1·kg−1), but the average %HRR achieved in the 6-min stage was 78%, with several subjects attaining heart rates considered too high for submaximal fitness testing. The second study also obtained a valid estimate of V̇O2max (r = 0.89, SEE = 4.0 mL·min−1·kg−1) with no over- or underestimation (mean estimated V̇O2max = 36.7 mL·min−1·kg−1, mean measured V̇O2max = 36.9 mL·min−1·kg−1), and the average %HRR achieved in the 6-min stage was 64%. Conclusions: A new method for estimating V̇O2max from submaximal cycling based on V̇O2 reserve has been found to be valid and more accurate than previous methods