Criteria for maximum oxygen uptake in progressive bicycle tests

Summary

Different criteria for $\dot V$O₂ max in a progressive bicycle exercise were studied in 115 healthy subjects. In the repeated progressive tests performed on 16 men, aged 25–35 years, three types of $\dot V$O₂ response against work load were noticed: a linear increase, an unexpectedly high increase, and a plateau; the last two only appearing when $\dot V$O₂ max was achieved. The last three $\dot V$O₂ values at least were required to define the plateau. Most commonly, subjective exhaustion was achieved, respiratory quotient (R) was over 1.15 and maximal heart rate (HR) at the estimated level for age, though $\dot V$O₂ max was not achieved. No significant differences were found between “peak $\dot V$O₂” in the first progressive test (mean=2.95 l/min), the second progressive test (mean=3.14 l/min), or the constant-load test (mean=3.05 l/min). In the progressive test performed once on 55 men and 44 women, aged 35–62 years, subjective exhaustion was achieved by most of the subjects, but the plateau in $\dot V$O₂ was shown only in 17 subjects, and the peak $\dot V$O₂ values were somewhat lower than expected. Moreover, R max did not correlate with peak $\dot V$O₂, and was over 1.15 only in 9 subjects, and HR max was often below the estimated level. Thus, the progressive test appeared to be convenient in testing the physical work capacity of the subjects, but the establishment of the physiological maximum was more difficult: the relatively uncommon plateau in $\dot V$O₂ was the only useful criterion for $\dot V$O₂ max, the value of other criteria being unacceptable.