Adherence and compliance with exercise training in progressive multiple sclerosis: Rates and correlates from the CogEx trial

Background: There is limited understanding of adherence and compliance rates for exercise training(ET) in people with progressive multiple sclerosis(PMS). Objectives: This secondary, exploratory data analysis examined rates of adherence and compliance for continuous, moderate intensity training and high-intensity interval training(HIIT) and possible correlates among people with PMS from the CogEx trial. Methods: CogEx was a multi-site, multi-arm, randomized, double-blinded, and sham-controlled trial undertaken by 11 sites in six different countries. Participants(N = 311) were randomized into one of four conditions with different combinations of ET and cognitive rehabilitation, including respective sham conditions, delivered twice weekly over 12 weeks. The analysis focused on adherence and compliance rates and correlates for participants in the pooled ET intervention conditions who received and attempted the ET intervention(n = 152). Results: The rates of adherence and compliance overall(combined for both training stimuli) were 94 % and 66 %, respectively. The rates of adherence and compliance for continuous, moderate-intensity exercise were 95 % and 73 %, respectively, and for HIIT were 92 % and 58 %, respectively. The multivariable regression indicated that better 6MWT performance predicted higher compliance(particularly with HITT), whereas better CVLT-II performance predicted higher adherence and compliance with continuous training in PMS. Conclusion: Our results highlight worse compliance than adherence with ET, particularly for HIIT, in PMS. We further highlight cognitive and physical function as correlates of adherence and compliance for consideration in future clinical trials of ET in PMS.