Consistent exercise timing as a strategy to increase physical activity: A feasibility study.

Area of Science:

• Exercise Physiology
• Behavioral Science

Background:

• Observational studies suggest consistent exercise timing may enhance moderate-to-vigorous physical activity (MVPA) in adults with obesity.
• The feasibility and acceptability of prescribed consistent exercise timing in free-living conditions remain unestablished.

Purpose of the Study:

• To assess the feasibility and acceptability of prescribed consistent exercise timing in a free-living setting among inactive adults with obesity.
• To compare MVPA timing prescriptions and characterize exercise barriers and facilitators.

Main Methods:

• A within-subjects design randomized 15 inactive adults with obesity to three 3-week conditions: consistent morning, consistent evening, and choice timing.
• Feasibility was measured against prespecified benchmarks, while acceptability and preference were assessed via questionnaires.
• MVPA, exercise timing, and barriers/facilitators were monitored using accelerometry and nightly surveys.

Main Results:

• All feasibility benchmarks were met, with timing adherence exceeding 60% via accelerometry and self-report.
• Consistent exercise timing was deemed acceptable (mean rating 3.7/5), though choice timing was most preferred.
• Consistent morning and evening exercise conditions showed medium-to-large effects on increasing MVPA compared to the choice condition.

Conclusions:

• Prescribed consistent exercise timing is feasible and acceptable for adults with obesity in free-living settings.
• Consistent timing, particularly morning or evening, appears more effective for increasing MVPA than choice timing.
• Further research in larger trials is warranted to confirm efficacy and explore mechanisms for promoting MVPA.