Three minutes of moderate-intensity stair walking improves glucose and insulin but not insulin sensitivity or total antioxidant capacity

Abstract

Background and aims: This study examined the effect of moderate intensity stair stepping exercise on the glycemic response, and antioxidant capacity (TAC) during an oral glucose tolerance test (OGTT).

Methods and results: Thirty participants (women = 12) completed 4 OGTTs during rest or stair walking bouts of 1, 3, and 10 min in a randomized order. Blood was collected at baseline and 30 min during the OGTTs and analyzed for glucose, insulin, TAC, and lactate. Glucose concentrations were decreased following the 10 min (-22.69 (-34.66 to -10.72) mg/dL, p < 0.002) and 3 min (-15.37 (-25.05 to -5.69) mg/dL, p < 0.004) bouts but not the 1 min bout (-6.18 (-19.54 to 7.18) mg/dL, p = 0.352). Insulin concentrations were decreased following the 10 min (-6.11 (-8.86 to -3.36 μIU/dL), p < 0.001) and 3 min (-2.589 (-4.54 to -0.63) μIU/dL, p < 0.012) bouts but not the 1 min bout (-0.37 (-1.87 to 1.13) μIU/dL, p = 0.616). Insulin sensitivity index values showed a significant increase in the 10-min trial (1.81 (0.03-3.58), p < 0.048), but not during the 3 min (0.65 (-0.66 to 1.96) p = 0.317) or 1 min trial (0.13 (-1.58 to 1.84) p = 0.878). There was no omnibus effect for trial in TAC (p = 0.132, η² = 0.07). There was no interaction between trial and time for blood lactate (p = 0.621, η² = 0.02).

Conclusion: This study provides evidence bouts as short as 3 min decrease postprandial blood glucose and insulin levels but longer bouts are needed to affect insulin sensitivity.

Keywords: Exercise; Hyperglycemia; Hyperinsulinemia; Stair-stepping.