A 10-s sprint performed prior to moderate-intensity exercise prevents early post-exercise fall in glycaemia in individuals with type 1 diabetes

Abstract

Aims/hypothesis We investigated whether a 10-s maximal sprint effort performed immediately prior to moderateintensity 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 moderateintensity exercise in individuals with type 1 diabetes.

Quantifying the Acute Changes in Glucose with Exercise in Type 1 Diabetes: A Systematic Review and Meta-Analysis

“…Of the remaining 17 articles, we decided not to include another eight studies in our meta-analysis due to three reasons that were identified post hoc, namely: (1) in five studies [20][21][22][23][24], patients were supplied with rescue dextrose or carbohydrates, which meant that glucose profiles were artificially altered by these emergency interventions; (2) two studies [25,26] consisted of a single 10 s sprint at the beginning/end of a session and could not therefore be strictly considered to be either CONT or IHE; and (3) one study [27] did not provide any data about inter-subject variability (mean population profiles only were given). During the process of peer review for this report, journal reviewers identified one extra study that fulfilled our inclusion criteria: Yardley et al [28].…”

Metabolic and hormonal response to intermittent high-intensity and continuous moderate intensity exercise in individuals with type 1 diabetes: a randomised crossover study

“…IHE consists of repeated bouts of supramaximal efforts interrupting longer periods of low to moderate intensity activity. So far, a limited number of studies have investigated IHE in type 1 diabetes, generally reporting a glycaemiastabilising effect when compared with continuous moderate intensity exercise (CONT) [4][5][6][7][8][9][10][11]. However, exercise in the majority of these studies was of limited duration and data regarding longer IHE duration are scarce [7].…”

Antecedent hypoglycaemia does not diminish the glycaemia-increasing effect and glucoregulatory responses of a 10 s sprint in people with type 1 diabetes

“…At approximately 15:00 hours, the participants performed a 10 s maximal sprint on a front-access cycle ergometer (Repco, Melbourne, VIC, Australia) as described previously [14,15]. They then rested in a seated position for the remainder of the 60 min recovery period.…”

“…Unless otherwise stated, all results are expressed as mean ± SEM. Our sample size was calculated based on published data on the effect of intense exercise on blood glucose levels, glucose Ra, glucose Rd and the levels of the glucoregulatory hormones [8][9][10][11][12][14][15][16]. This sample size was calculated with a power of 1−β=0.8 and statistical significance was set at p<0.05.…”

“…For this reason, we have recently investigated whether a 10 s maximal sprint effort may be useful for hypoglycaemia prevention. We have shown that in young adults with type 1 diabetes a 10 s maximal sprint performed before or after moderate-intensity exercise (40% V O 2max ) while plasma insulin levels are elevated prevents blood glucose from falling after exercise, thereby reducing their risk of exercise-mediated hypoglycaemia [14,15]. More recently, we have also shown that performing a 10 s sprint under basal insulin conditions causes a significant and sustained rise in blood glucose level in young adults with type 1 diabetes [16].…”