4. Discussion
migraine, CM
MIGRAINE
This is the first study to investigate time-of-day and chronotype-dependent regulation of exercise-induced benefits in people with CM, and we identified a potentially important role for exercising in synchrony with chronotype. While a growing number of studies investigate exercise timing, very few account for the chronotype of participants. In a recent systematic review conducted by Vitale et al., they found only ten published articles that examined the effect of chronotype on exercise performed at different times of day. None of the papers reported in this review had participants exercise over a longer period than one day [Although participants were instructed to complete at least three 30-min exercise sessions each week, we only had moderate adherence (~75%, not different between ME and EE, but slightly higher for IS compared to OOS). This was, indeed, interesting from a practical standpoint, and emphasized a novel way in which exercise adherence may be improved. This constituted a relatively mild exercise intervention that fell near, or below, generally recommended exercise prescriptions to see health benefits (ACSM). However, this exercise dose was sufficient to induce clinically meaningful reductions in migraine load. We found no effects of any exercise condition (ME vs. EE, or IS vs. OOS) on exercise intensity (based on average HR) or duration, though HR tended to be higher during EE and IS exercise (not significant). As such, exercise-induced improvements to migraine load observed in the current study were independent of overt differences in the exercise prescription.