Exercise time of day and blood pressure: Considering chronotype for precision health

The health benefits of exercise among people at risk for cardiovascular disease (CVD) are well accepted. However, many health professionals and researchers debate the optimal exercise “dose” (e.g. intensity, modality, and/or duration) for improving cardiometabolic health [ 1 , 2 ]. In recent years, the best time of day to exercise has become a popular and open question, as research has primarily focused on morning versus afternoon timeframes. A practical consideration here is that time is often reported as a major barrier to exercise. Advising people to simply move when they can, seems to be a reasonable recommendation. A trick though for at least many adults relates to weekly work schedules that may limit the ability to dedicate time to exercise in the morning or afternoon. Pre-planning nonetheless can be an advantage when considering the time of day to exercise. Thus, empowering people to select when they feel is best to exercise would be anticipated to lead to long-term adherence. Chronotype is a term in circadian biology used to describe “early birds” and “night owls” with respect to performing various acts of daily living, including eating, physical activity, sleep, and work preferences [ 3 ]. But, whether exercise impacts health in relation to chronotype is not clear.