Aims/hypothesis  

We investigated whether a 10-s maximal sprint effort performed immediately prior to moderate-intensity exercise provides another means to counter the rapid fall in glycaemia associated with moderate-intensity exercise in individuals with type 1 diabetes.

Materials and methods  

Seven complication-free type 1 diabetic males (21.6 ± 3.6 years; mean±SD) with HbA_1c levels of 7.4 ± 0.7% injected their normal morning insulin dose and ate their usual breakfast. When post-meal glycaemia fell to ∼11 mmol/l, participants were asked to perform a 10-s all-out sprint (sprint trial) or to rest (control trial) immediately before cycling at 40% of peak rate of oxygen consumption for 20 min, with both trials conducted in a random counterbalanced order.

Results  

Sprinting did not affect the rapid fall in glycaemia during the subsequent bout of moderate-intensity exercise (2.9 ± 0.4 mmol/l in 20 min; p = 0.00; mean±SE). However, during the following 45 min of recovery, glycaemia in the control trial decreased by 1.23 ± 0.60 mmol/l (p = 0.04) while remaining stable in the sprint trial, subsequently decreasing in this latter trial at a rate similar to that in the control trial. The large increase in noradrenaline (norepinephrine) (p = 0.005) and lactate levels (p = 0.0005) may have contributed to the early post-exercise stabilisation of glycaemia in the sprint trial. During recovery, adrenaline (epinephrine) and NEFA levels increased marginally in the sprint trial, but other counter-regulatory hormones did not change significantly (p < 0.05).

Conclusions/interpretation  

A 10-s sprint performed immediately prior to moderate-intensity exercise prevents glycaemia from falling during early recovery from moderate-intensity exercise in individuals with type 1 diabetes.