The Effect of Acute Aerobic Exercise On the Time Spent in Hypoglycaemia After Bariatric Surgery (The BariEX Study)

OBJECTIVE: To determine whether a pre-lunch single bout of moderate-intensity aerobic exercise (AEX) alters time spent in hypoglycaemia (<3.0 mmol/L) during the subsequent 24 hours (24-h) and parameters of glucose homeostasis in individuals without diabetes after metabolic/bariatric surgery (MBS). METHODS: In a randomised crossover study, 15 participants completed two conditions: 30min treadmill walking at 60% V̇O₂peak (AEX) and time-matched sitting (CON). After an overnight fast and a standardised breakfast, participants performed AEX or CON, and both conditions were followed by an identical lunch administered as a mixed-meal tolerance test (MMTT). Continuous glucose monitoring (CGM) assessed glucose levels for 24-h post-intervention, during which participants consumed standardised meals. CGM data were available for analysis in 11 participants. The primary outcome was time spent with glucose <3.0 mmol/L during the 24-h post-intervention. Secondary outcomes included other CGM-derived glucose metrics and plasma glucose and insulin responses during the 3-h MMTT. RESULTS: glucose, as well as pre-MMTT insulin concentrations, were higher following AEX (all p < 0.05). CONCLUSIONS: A pre-lunch 30-min bout of AEX did not increase the 24-h risk of hypoglycaemia post-MBS but elevated post-MMTT glucose levels.