Post-exercise Glucose Response Following Whey Protein Ingestion in Healthy Young People: A Randomized Pilot Study

Abstract

Whey protein may have an effect directly on the muscle to affect exercise glucose response.The study aimed to measure post-exercise glucose recovery with supplementation and the role of DPP-IV and IL-6.Twenty-four participants were randomly assigned to one of three supplementation conditions (CTL: water, WPI: 31g whey protein isolate, and CHO: 32g fructose beverage; WPI and CHO beverages were isocaloric). During the Baseline Visit, participants performed an Oral Glucose Tolerance Test (OGTT) with no exercise or supplementation. On their second and third visits, participants consumed their assigned beverage then completed a maximal treadmill protocol until volitional fatigue. An OGTT was completed on the second visit, and blood samples were collectedviavenipuncture on the third visit for IL-6, Insulin and DPP-IV.Glucose delta peak was attenuated in WPI+exercise by -45±25% and CHO+exercise by -49±21%, compared to baseline (p<0.05). Glucose area under the curve was only attenuated with WPI+exercise (5,993±1,013mg/dl*min), compared to baseline (10,604±4,589mg/dl*min; p<0.05). Insulin was elevated in the WPI+exercise (111±57pmol/L) and CHO+exercise (119±70pmol/L), compared to rest (WPI: 61±40pmol/L; CHO: 78±56pmol/L; p<0.05). IL-6 and DPP-IV activated T-cells (CD26+) were not different among groups. However, plasma DPP-IV was higher in WPI (8±6U/L) compared to CTL (0.7±2U/L) and CHO (0.6±4U/L; p<0.05).We found that a single dose of whey protein given prior to exercise results in elevated DPP-IV activity in the plasma and improved glucose response. Together these data suggest that whey protein as a supplement to exercise may be beneficial for humans trying to manage their blood sugar.