A Novel Custom Cycle Ergometer Protocol to Determine V̇O2max: Validation with ACSM’s Cycle Ergometry Metabolic Equation

Abstract

ABSTRACT Introduction Protocols for determination of maximal oxygen consumption (V̇O 2max ) on a cycle ergometer should be easily administered while maximizing physiological efficiency and minimizing premature local muscle fatigue for individuals of variable fitness levels. Current protocols typically increase workload by adding resistance to the flywheel; however, increasing pedal rate later in the test, rather than resistance, may provide increased physiological efficiency, yielding a more valid determination of V̇O 2max . Purpose The purpose of this study was to design and validate a novel V̇O 2max cycle ergometer protocol that can be used for measuring and predicting submaximal oxygen consumption (V̇O 2 ) and V̇O 2max during exercise testing in healthy, asymptomatic adults. Methods Subjects ( n = 60, 19–60 yr old) performed a V̇O 2max test using the new cycle ergometer protocol. Workload increases were based on predetermined incremental target heart rates (ITHR) using heart rate reserve. Stages commenced at a workload of 150 kg · m · min −1 (0.5 kg, 50 rpm) and increased every 2 min by adding 0.5 or 1.0 kg resistance based on ITHR. When an ITHR representing ≥60% heart rate reserve was achieved, workloads increased by 10 rpm for subsequent stages. Pearson’s r was used to examine relationships between predicted (American College of Sports Medicine cycle equation) and measured V̇O 2 at workload intensities representing moderate, vigorous, and maximal exercise. Bland–Altman plots were used to display predicted and measured V̇O 2 at all exercise intensities and heart rate values at maximal exercise. Results There was a strong and statistically significant correlation between predicted and measured V̇O 2 at moderate ( r = 0.92, P < 0.001), vigorous ( r = 0.94, P < 0.001), and maximal ( r = 0.90, P < 0.001) exercise intensities. All subjects reached ≥90% of age-predicted maximum heart rate. Conclusion This novel cycle ergometer protocol was demonstrated to be a viable tool to predict and/or measure submaximal V̇O 2 and V̇O 2max in a population of healthy, asymptomatic adults.