Effects of high-intensity interval exercise versus continuous moderate-intensity exercise on postprandial glycemic control assessed by continuous glucose monitoring in obese adults

TLDR

The study examined whether a single bout of high‑intensity interval training (HIIT) reduces post‑prandial hyperglycemia more than continuous moderate‑intensity exercise (CMI) in overweight or obese adults. Ten inactive, overweight or obese adults performed either 10×1‑minute HIIT at ~90% peak heart rate with 1‑minute recoveries or 30‑minute CMI at ~65% peak heart rate, with exercise 2 h after breakfast; continuous glucose monitoring over 24 h under standardized meals measured post‑prandial glucose responses to lunch, dinner, and the next day’s breakfast compared to a no‑exercise control. Both HIIT and CMI lowered dinner post‑prandial glucose AUC versus control, but HIIT uniquely reduced the next‑day breakfast AUC and spike, indicating that a single HIIT session yields greater and more lasting reductions in incremental post‑prandial glucose than CMI.

Abstract

The purpose of this study was to examine the impact of acute high-intensity interval training (HIIT) compared with continuous moderate-intensity (CMI) exercise on postprandial hyperglycemia in overweight or obese adults. Ten inactive, overweight or obese adults (41 ± 11 yrs, BMI = 36 ± 7 kg/m 2 ) performed an acute bout of HIIT (10 × 1 min at approximately 90% peak heart rate (HR peak ) with 1-min recovery periods) or matched work CMI (30 min at approximately 65% HR peak ) in a randomized, counterbalanced fashion. Exercise was performed 2 h after breakfast, and glucose control was assessed by continuous glucose monitoring under standardized dietary conditions over 24 h. Postprandial glucose (PPG) responses to lunch, dinner, and the following day’s breakfast were analyzed and compared with a no-exercise control day. Exercise did not affect the PPG responses to lunch, but performing both HIIT and CMI in the morning significantly reduced the PPG incremental area under the curve (AUC) following dinner when compared with control (HIIT = 110 ± 35, CMI = 125 ± 34, control = 162 ± 46 mmol/L × 2 h, p < 0.05). The PPG AUC (HIIT = 125 ± 53, CMI = 186 ± 55, control = 194 ± 96 mmol/L × 2 h) and the PPG spike (HIIT = Δ2.1 ± 0.9, CMI = Δ3.0 ± 0.9, control = Δ3.0 ± 1.5 mmol/l) following breakfast on the following day were significantly lower following HIIT compared with both CMI and control (p < 0.05). Absolute AUC and absolute glucose spikes were not different between HIIT, CMI, or control for any meal (p > 0.05 for all). We conclude that a single session of HIIT has greater and more lasting effects on reducing incremental PPG when compared with CMI.