Physical activity, sedentary behavior, and aerobic capacity in persons with multiple sclerosis

Abstract

Background: There is substantial evidence that exercise training improves aerobic capacity among people with multiple sclerosis (MS), but less is known about the associations between physical activity and sedentary behaviors with aerobic capacity.

Objective: This study examined if objectively-measured moderate-to-vigorous (MVPA) and light (LPA) physical activity and sedentary behavior were associated with peak aerobic capacity (VO₂peak) measured using an established protocol for conducting a maximal, incremental exercise test in persons with MS.

Methods: The study involved a cross-sectional, observational study design and included 49 persons with MS. Participants wore an accelerometer around the waist during the waking hours for a 7-day period as a measure of physical activity and sedentary behaviors, and completed a maximal, incremental exercise test on an electronically-braked, computer-controlled cycle ergometer with open-circuit spirometry for measuring VO₂peak.

Results: VO₂peak was significantly correlated with MVPA (r=0.53, p<0.001) and LPA (r=0.39, p<0.01), but not sedentary behavior (r=-0.12, p=0.44). Linear regression analysis indicated that MVPA (B=0.19, SE B=0.04, β=0.51, p<0.001) and LPA (B=0.02, SE B=0.01, β=0.30, p<0.05), but not sedentary behavior (B=-0.01, SE B=0.01, β=-0.14, p=0.26), explained significant variance in VO₂peak (R²=0.40).

Conclusion: We provide the first evidence that MVPA and LPA represent concurrent correlates of VO₂peak and both could be targeted for improving aerobic capacity in persons with MS.

Keywords: Aerobic capacity; Fitness; Moderate-to-vigorous physical activity; Multiple sclerosis; Sedentary behavior.