To Örebro University

OBJECTIVE: Increased levels of physical activity is often associated with reduced HbA1c in individuals with diabetes. However, the effect on glycemic control differs between different programs of exercise. The aim of this study was to compare the acute effects on glycemia of resistance and two aerobic continuous and intermittent exercise bouts in adolescent males with type 1 diabetes.

METHODS: Eight active males with type 1 diabetes (17.5±0.8 years, BMI: 20.8±2.2 kg/m² , HbA1c: 7.2±0.5 % (54.9±5.3 mmol/mol)) performed four experimental sessions - non-exercise (control), resistance exercise (RE) and two isocaloric continuous (CE) and intermittent (IE) cycling exercise trials - in a randomized order. Each session consisted of 45 minutes of exercise (except for the control modality) and 60 minutes of passive recovery. Venous blood was drawn for assessment of plasma glucose (PG). A two-way repeated-measures ANOVA was used for statistical comparisons.

RESULTS: A significant time-to-exercise interaction effect on PG was detected. PG significantly decreased during IE (-5.1±1.6 mmol/L) and CE (-5.4 ± 1.8 mmol/L) but not during RE (-1.0 ± 1.4 mmol/L, ns). Additionally, decreases in PG after IE and CE were sustained throughout the recovery period.

CONCLUSIONS: While intermittent and continuous aerobic exercises are associated with a lowering of glycemia in male adolescents with type 1 diabetes, glycemia remained stable without significant alterations after resistance exercise. These findings hold important implications related to clinical exercise advice and disease management in adolescents with type 1 diabetes.