Response variability to exercise (REVISE): Study rationale, design and methods

Abstract

Physical inactivity and low levels of cardiorespiratory fitness (CRF, VO₂peak) are major threats to public health. In response, leading health authorities worldwide recommend that all adults accumulate 150 min/wk of moderate to-vigorous physical activity. However, we and others have demonstrated an extraordinary inter-individual variability in CRF response to standardized exercise wherein a substantial number of adults may not improve CRF beyond day-to-day variability. Whether CRF response to first line therapy is a permanent feature of the individual or can be altered by increasing exercise dose is unknown. We will perform a single-centre, two-phased, randomized controlled trial. In Phase I we will randomly assign previously inactive, adult men and women between 25 and 65 years in a 1:9 ratio to a no-exercise wait-list control, or a low amount, low intensity (∼150 min/wk) group for 16 weeks. In Phase II (16 weeks), participants randomized to exercise in phase I will be re-randomized to 1 of 3 exercise groups: 1) the same low amount, low intensity; 2) low amount, high intensity, or 3) high amount, high intensity. The primary outcome is CRF. Our primary question is, after 16 weeks of ∼150 min/wk of moderate intensity exercise, does increasing exercise intensity or exercise amount for an additional 16 weeks improve CRF differently depending on the response to exercise during the first 16 weeks? The findings will provide first evidence and immense opportunity for development of a more personalized approach to exercise that recognizes individual response variability.

Trial registration: clinicaltrials. gov identifier: NCT05496751.

Keywords: Cardiorespiratory fitness; Exercise; Individual response; Physical activity.

Fig. 1

Study design.

Fig. 2

Exercise prescription.