The effect of different exercise intensities on glucose tolerance in young, healthy, and moderately active women

Abstract

Purpose: Around 350 000 people have impaired glucose tolerance in Norway to this day. Among these, 1 out of 3 develops type 2 diabetes mellitus (T2DM) within 10 years’ time. Physical activity and exercise have proven to increase glucose uptake in the skeletal muscle, and it is interesting to investigate if exercise of high intensity, low duration has a superior effect on glucose tolerance compared to continuous moderate exercise. Oral glucose tolerance test (OGTT) is normally used when investigating an effect on glucose tolerance. For this present study, it was used a continuous glucose measurement (CGM) device.

Method: Four adult, moderately active and healthy women (age=28± 3.5, BMI=22.8± 1.9, VO2max=47.1± 3.9 ml/kg/L) completed a three-week training intervention wearing CGM device. The participants performed two high intensity interval exercise (HIIE) sessions at 85-95% HRmax or two continuous moderate exercise (CME) sessions at 70% HRmax on a bicycle, in a counterbalanced order with seven days of rest in between. They were given a standardized dinner after completed exercise and a standardized breakfast for the day after.

Results: Post-prandial glucose (PPG) after breakfast was reduced in the week with CME compared to HIIE (CME= 5.8±0.9 mmol/L to HIIE= 6.5±1.0 mmol/L, p=0.019), but not compared to control week. The PPG after dinner was reduced in the week with HIIE compared to CME (HIIE=5.3±0.3 mmol/L to CME=5.6±0.6 mmol/L, p=0.028) and in the control week compared to CME (CON= 5.3±0.2 mmol/L to CME= 5.6±0.6 mmol/L, p=0.001). No significant reductions in fasting glucose values.

Conclusion: This present study observed that a single bout of exercise improved glucose tolerance after a standardized breakfast and dinner.