Baseline functional oxygen uptake gain as a prognostic factor of center-based exercise responding in well-functioning older adults.

It was a single-center, single-arm pre-post study from an intervention arm of a prospective cohort, so there was no comparison group to separate exercise changes from other changes over time. Exercise responders were defined after follow-up using a peakVO2 change cutoff of 2.5 mL/kg/min, so the analysis is post-hoc, not a randomised comparison. Participants were community-dwelling, non-disabled older adults of Han ethnicity able to walk 400 meters in 15 minutes without assistance, so findings may not apply to more disabled or diverse populations. Attrition occurred: 180 enrolled, 151 analyzed at 1 year, and 91 completed 2 years. The authors note potential attrition bias, but their sensitivity analysis did not substantially change the main conclusions. The prognostic marker required cardiopulmonary exercise testing, which the authors note may limit routine use outside specialist settings.

The authors declared no financial conflicts of interest. The work was funded by Fujian Health Committee, Fujian Medical University, Fujian Natural Science Foundation, Fujian Provincial Department of Science and Technology, and a Central Leading Local Science and Technology Development Special Fund Project.

Do not read the 9.310 mL/min/W cutoff as a reliable clinical classifier. It had sensitivity 44.74% and specificity 89.38%, and the study had no comparison group, so it shows an association, not a tested treatment effect.