PURPOSE: Examine if stair stepping (SS) bouts at a self-selected intensity with individual timing can attenuate postprandial blood glucose (PBG). METHODS: Over 3 visits participants completed 3 mixed meal tolerance tests (700 kcal, 51% CHO, 34% fat, 15% PRO) with PBG measured at baseline and every 10 minutes after food consumption. The first visit was a seated control condition to find timing of peak PBG. The second and third visits were randomized and included either 1 or 3 min of SS timed to end right before individual peak PBG. Glycemic excursions were assessed as a glucose over time in a 3(condition)x7(time) RM ANOVA, baseline to peak PBG in a 3(condition)x2(time) RM ANOVA, and AUC and iAUC in one-way RM ANOVAs. RESULTS: For glucose over time there were main effects for condition [F(2,42) = 6.41, p < .004, η2 = .23] and time [F(6,126) = 24.584, p < .001, η2 = .54] but no interaction between condition and time [F(12, 252) = 1.12, p < .35, η2 = .05]. PBG was lower during the 3 min SS than the control and 1 min SS conditions at min 20 ((-16 (-24 to -8) mg/dL, p < .001) and (-9 (-18 to 0) mg/dL, p = .047)) and min 30 (((-11 (-20 to -2) mg/dL, p = .021) and (-10 (-20 to 0) mg/dL, p = .047))) but not at other timepoints (p = .078-.191). (Figure 1A) For baseline to peak PBG there were main effects for condition [F(2,42) = 7.27, p < .002, η2 = .26] and time [F(1,21) = 189.97, p < .001, η2 = .90] and an interaction between condition and time [F(2,42) = 5.10, p < .010, η2 = .20]. Peak PBG was lower than control in the 1 min SS (-7 (-12 to -1) mg/dL, p = .024) and 3 min SS (-14 (-21 to -7) mg/dL, p < .001) conditions. (Figure 1B) There was a main effect for AUC [F(2,42) = 6.416,p = .004,η2 = .234] with lower PBG in the 3 min SS than the control and 1 min SS conditions ((-7% (-11% to -3%) mg/dL/hr, p < .001) and (-5% (-10% to 0%) mg/dL/hr, p = .041)) (Figure 1C) but not for iAUC [F(2,42) = 2.541, p = .091,η2 = .108] (Figure 1D) CONCLUSION: SS with individualized timing for as little as 1 minute can lower PBG with greater reductions with 3 minutes of SS.