Greater Adherence to Recommended Morning Physical Activity is Associated With Greater Total Intervention-Related Physical Activity Changes in Bariatric Surgery Patients

Abstract

Background This study examines whether performance of bout-related physical activity (PA) during morning hours is related to greater overall bout-related PA increases within a preoperative PA intervention for bariatric surgery (BS) patients. Methods Participants with severe obesity (n = 33; mean age = 45.6 ± 9.6 years; BMI = 45.7 ± 7.0 kg/m2) seeking BS were randomized to and completed 6 weeks of preoperative PA counseling (retention = 82.5%). Participants were encouraged to walk daily at a moderate intensity in bouts ≥ 10 minutes during morning hours to overcome time-related obstacles and establish a PA habit. Timing and amount of bout-related moderate-to-vigorous PA (MVPA) was assessed via objective monitor at pre- and postintervention. Results Greater proportion of bout-related MVPA performed during morning hours (4:00 AM–12:00 PM) at postintervention was associated with larger total increases in bout-related MVPA minutes/day (β = .40, P = .03). At postintervention, a greater proportion of participants whose longest MVPA bouts occurred during morning hours (n = 11) achieved the public health guideline (ie, ≥150 bout-related MVPA minutes/week) versus those whose longest MVPA bouts occurred during nonmorning hours (n = 19; 63.6% vs. 26.3%, P = .04). Conclusions Intervention-related increases in PA tended to be greatest when PA was performed in the morning. Morning exercise may be a viable strategy for promoting habitual PA in inactive BS patients.

Relationship of Consistency in Timing of Exercise Performance and Exercise Levels Among Successful Weight Loss Maintainers

“…Among those who reported a temporally consistent PA routine, early morning was the most common time that exercise was performed, followed by evening. In contrast with our hypothesis and previous work , the particular time of day at which temporally consistent exercisers most often performed PA was not differentially related to PA levels. Our findings thus add to the mixed literature on the optimal time of day, if any, for PA. Because all temporally consistent exercisers in the present study reported, by definition, exercising at the same time day to day, it is likely that these individuals had well‐established PA routines.…”

“…Our findings thus add to the mixed literature on the optimal time of day, if any, for PA. Because all temporally consistent exercisers in the present study reported, by definition, exercising at the same time day to day, it is likely that these individuals had well‐established PA routines. Perhaps among individuals who have already established a strong PA habit, the particular time of day at which PA is performed is less important than overall temporal consistency in PA. As indicated by prior research, however, morning PA performance may be especially important for initially developing a PA habit and for PA adoption . The finding that nearly half of temporally consistent exercisers were early‐morning exercisers also suggests that performing PA in the early morning may be helpful for maintaining a regular PA routine, although these individuals were not more active than their counterparts in the present study and we cannot determine causality from the present data.…”

“…MVPA was also self‐reported. Self‐reports of PA may be biased and subject to overestimation , and assessment of MVPA via questionnaire (versus accelerometer) may have impacted our ability to compare our findings to past work regarding the relation between specific time of day of PA and overall MVPA levels . Assessment occurred at only one time point.…”

“…Thus, participants exercising 2 d/wk had to report both exercise sessions within the same time window to be categorized as temporally consistent, individuals exercising 3 d/wk had to report ≥ 2 exercise sessions within the same window, individuals exercising 4 d/wk had to report ≥ 3 exercise sessions within the same window, and so on. This categorical timing scheme was modeled off of prior studies . However, as noted, we further differentiated early‐ and late‐morning exercisers because of potential biological and behavioral benefits of early‐morning PA.…”

“…In addition to the potential importance of temporal consistency or inconsistency for PA levels, the particular time of day that PA is performed might also have implications for weight management. While research in this area has been limited, one study found that older women who were more active in the morning were at lower risk for obesity , and another found that adults who performed a greater proportion of their PA in the morning more successfully increased PA prior to bariatric surgery . Although these findings are initially supportive of the importance of morning PA, there is a need for additional research.…”