Can linear regression confirm VO₂max was attained in middle-aged and older adults?

Purpose: Evaluate the efficacy of a regression method for identifying a VO₂ plateau to confirm the attainment of VO₂max compared to a verification trial in middle-aged and older adults.

Methods: Eleven men and ten women (age 61.0 ± 8.1, VO₂max 21.8-50.3 ml/kg/min, n = 21) completed an individualized ramp graded exercise test (GXT) on the cycle ergometer, and one hour later, a verification trial at 105% of their maximal work rate (WR) achieved during the GXT. A plateau in VO₂ was used to confirm VO₂max was attained. VO₂ plateau was identified using the difference between the highest VO₂ between the two trials and a linear regression analysis of the VO₂-WR relationship during the GXT. McNemar's test of marginal homogeneity was used to detect differences in the proportion of paired data of individuals' attainment of VO₂max criteria.

Results: Of the 21 participants, 15 (71.4%) met the verification criterion while 6 (28.6%) did not, compared to the regression method where 16 (76.2%) achieved the regression criterion while 5 (23.8%) did not. McNemar's test revealed no significant difference between participants' ability to achieve the regression and verification criteria (p = 0.999).

Conclusion: The regression method is an effective strategy for confirming VO₂max was attained with middle-aged and older adults on a cycle ergometer. This time-efficient regression method is comparable with the verification criterion but does not require a second maximal test, which may be advantageous for those where the verification trial may not be practical.