Prevalence Of Vo2max Low Response Across Nine Aerobic Exercise Interventions

There is considerable inter-individual variation in the ability to improve VO2max in response to regular exercise. Thus, identifying individuals who do not experience clinically significant gains in cardiorespiratory fitness with aerobic training (i.e., VO2max low response) is of interest. PURPOSE: To assess the prevalence of VO2max low response across nine large aerobic exercise interventions. METHODS: The prevalence of VO2max low response was examined in 1,432 previously sedentary adults (461 males, 971 females) who completed one of nine exercise programs from five exercise training studies: DREW (n=361), E-MECHANIC (n=117), Energy Flux (n=65), GERS (n=171), and HERITAGE (n=715). The training programs ranged from doses of 4-35 kcal·kg-1·week-1 (KKW); intensities of 50-85% VO2max; and durations of 20-24 weeks. Baseline and post-training VO2max was assessed via maximal exercise testing. VO2max low response was defined in both absolute (gain <120 ml/min from baseline value) and relative (gain < 5% of study-specific baseline average VO2max) terms based on technical error and coefficient of variation values derived from three repeatability studies in HERITAGE. RESULTS: All studies showed significant mean increases in VO2max with training. Using the above definitions, 32.6% (absolute) and 21.3% (relative) of the total sample was considered low responsive for VO2max. The distribution of low response across the individual exercise programs is shown in Table 1. Prevalence of low response ranged from 7.4% (HERITAGE) to 84% (DREW 4 KKW). CONCLUSION: Our study found a high prevalence of VO2max low response across five diverse exercise training studies, which differed based on how low response was defined. These results underscore the need for further investigation to refine the identification of VO2max low response to enhance future exercise program development.