This study examined if reductions in evening basal insulin can minimize overnight hypoglycemia following afternoon high-intensity interval training (HIIT) exercise in adults with type 1 diabetes.

In a randomized, two-arm crossover trial participants each undertook on separate days: moderate-intensity continuous exercise with 20% overnight basal insulin reduction (CONT20), and a series of 3 HIIT isocaloric sessions, with 10% (HIIT10), 20% (HIIT20) and 30% (HIIT30) overnight basal insulin reduction. Post-exercise glucose response was measured by Freestyle Libre Pro Flash Glucose Monitoring, and compared with a non-exercise day (NON). Participants were given standardised instructions throughout to reduce dinner insulin bolus by 25% post-exercise, have a bedtime snack, and to ensure pre-bed glucose >7.0mM.

Twelve adults participated (9F/3M, 9 MDI/3 CSII, mean age 40.4 ± 9.9y, duration 16.5 ± 9.8y, HbA1c 8.0 ± 0.8%, and BMI 26.9 ± 5.2kg/m2). Whilst overnight glucose profiles were not significantly different across all regimens (Table), the smallest change in glucose from 2300 to 0600 was seen after HIIT30, compared with other exercise regimens. Glucose profiles were not significantly different 24h post each regimen (p=0.28).

Thus, while data suggests HIIT30 may be a preferred approach, there were no differences in hypoglycemia rates in exercise regimens applied in this study.


A.S. Lee: None. K.L. Way: None. N.A. Johnson: None. S.M. Twigg: Advisory Panel; Self; Abbott. Consultant; Self; Abbott. Advisory Panel; Self; Novo Nordisk Inc., Sanofi-Aventis, AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company. Speaker's Bureau; Self; AstraZeneca, Merck Sharp & Dohme Corp.. Other Relationship; Self; Abbott.

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