The acute effects of moderate-intensity continuous or high-intensity interval exercise on appetite and appetite-related hormones in South Asian and white European adults with non-diabetic hyperglycaemia.

Objective: To compare acute effects of continuous moderate-intensity exercise (CME) and low-volume high-intensity interval exercise (LV-HIIE) on appetite responses between South Asians and white Europeans with non-diabetic hyperglycaemia.

Methods: Thirteen white Europeans and 10 South Asians (age 50-74 years) completed three, 5-h experimental conditions (CME, LV-HIIE, control) in randomised sequences. Standardised meals were provided at 0 and 3 h. Exercise involved a 25-min LV-HIIE or 35-min CME bout that ended at 2 h. Subjective appetite perceptions and appetite-related hormones (glucagon-like peptide-1 (GLP-1), peptide YY (PYY), acylated ghrelin (AG)) were measured at 0, 0.5, 1, 2, 3, 3.5, 4 and 5 h. Time-averaged total area under the curve (TAUC; 1-5 h) was analysed, adjusted for age, sex, and pre-intervention time-averaged TAUC (0-1 h).

Results: Total GLP-1 was higher in LV-HIIE (mean difference [95% CI] 4.3 [1.5, 7.1] pmol/L h) and CME (4.5 [1.4, 7.7] pmol/L h) versus control (condition effect P = 0.01), but exercise had no effect on the other outcomes in the whole study population (P ≥ 0.28). Appetite responses to exercise were similar between ethnicities for total GLP-1 and total PYY (interaction P ≥ 0.11), but subtle differences emerged for AG and overall appetite (interaction P ≤ 0.02). AG was higher and overall appetite lower in LV-HIIE versus CME in South Asians whilst overall appetite was higher in LV-HIIE versus CME in white Europeans, but neither exercise bout was different to control.

Discussion: Single LV-HIIE and CME bouts increased total GLP-1 in individuals with non-diabetic hyperglycaemia, but exercise-related appetite responses were not strongly modulated by exercise intensity or ethnicity.