The Effects Of Stair Stepping On Circadian Dependent Postprandial Glycemic Responses

PURPOSE: The purpose of this study was to test whether short (≤10 min), single bouts of stair stepping at a self-selected comfortable pace can reduce blood sugar after each meal (i.e. breakfast, lunch and dinner) in free-living adults. METHODS: 20 healthy participants (13 female, 7 male, age 20-30y) were fitted a continuous glucose monitor to wear throughout their normal daily life. Glucose was measured every 5 min. Participants performed stair stepping bouts of varying durations (1, 5 or 10 min) 15 minutes after each meal on separate days across a six-day period. Stair stepping bout lengths were consistent throughout a given day. Each stair stepping day was ‘paired’ with a control day where physical activity was restricted 1 h post-meal. Participants were instructed to not vary their normal diet and physical activity and keep it as consistent as possible within each pair of days. Diet and physical activity logs were collected to verify compliance. RESULTS: Blood glucose area under the curve was not different between stair stepping compared to control condition for 1 min (mean difference = -130(462)mg/dL*min, p = 0.35) or 10 min (-24(667) mg/dL*min, p = .78) but lower with 5 min stair stepping (-316(567)mg/dL*min, p = .03). The glucose reduction effect for the 5 min condition was robust across all meals (interaction p = .84, main effect p = .18). Similarly, changes from baseline to peak postprandial values were not different in the 1 min (-4(23)mg/dL, p = .30) and 10 min (4(36)mg/dL, p = .54) conditions but reduced in the 5 min condition (-16(32)mg/dL, p = .05) across all meals (interaction p = .28, main effect p = .67). CONCLUSIONS: In free-living conditions, short, single bouts of post-meal stair stepping at a self-selected comfortable pace for 5 min were sufficient to reduce postprandial blood glucose excursions. 1 min bouts were not enough while 10 min bouts appeared excessive to elicit a similar response resulting in null effects. Supported by: SDSU Seed Grant 2024 (internal)