Extremely short duration interval exercise improves 24-h glycaemia in men with type 2 diabetes

Abstract

PurposeReduced-exertion high-intensity interval training (REHIT) is a genuinely time-efficient exercise intervention that improves aerobic capacity and blood pressure in men with type 2 diabetes. However, the acute effects of REHIT on 24-h glycaemia have not been examined.Methods11 men with type 2 diabetes (mean ± SD: age, 52 ± 6 years; BMI, 29.7 ± 3.1 kg/m2; HbA1c, 7.0 ± 0.8%) participated in a randomised, four-trial crossover study, with continual interstitial glucose measurements captured during a 24-h dietary-standardised period following either (1) no exercise (CON); (2) 30 min of continuous exercise (MICT); (3) 10 × 1 min at ~ 90 HRmax (HIIT; time commitment, ~ 25 min); and (4) 2 × 20 s ‘all-out’ sprints (REHIT; time commitment, 10 min).ResultsCompared to CON, mean 24-h glucose was lower following REHIT (mean ± 95%CI: − 0.58 ± 0.41 mmol/L, p = 0.008, d = 0.55) and tended to be lower with MICT (− 0.37 ± 0.41 mmol/L, p = 0.08, d = 0.35), but was not significantly altered following HIIT (− 0.37 ± 0.59 mmol/L, p = 0.31, d = 0.35). This seemed to be largely driven by a lower glycaemic response (area under the curve) to dinner following both REHIT and MICT (− 11%, p < 0.05 and d > 0.9 for both) but not HIIT (− 4%, p = 0.22, d = 0.38). Time in hyperglycaemia appeared to be reduced with all three exercise conditions compared with CON (REHIT: − 112 ± 63 min, p = 0.002, d = 0.50; MICT: -115 ± 127 min, p = 0.08, d = 0.50; HIIT − 125 ± 122 min, p = 0.04, d = 0.54), whilst indices of glycaemic variability were not significantly altered.ConclusionREHIT may offer a genuinely time-efficient exercise option for improving 24-h glycaemia in men with type 2 diabetes and warrants further study.

Time-efficient and computer-guided sprint interval exercise training for improving health in the workplace: a randomised mixed-methods feasibility study in office-based employees

“…A legitimately raised question has been whether the fidelity and efficacy of REHIT can be replicated when performed unsupervised in a 'realworld' setting. During the all-out sprints in this study, participants achieved peak power outputs approximately 2.8-fold higher than they achieved during the V O 2 max test and this is similar to that observed in participants of similar age and body composition in a supervised laboratory-controlled environment [30]. This provides at least indirect evidence that the fidelity of the 'all-out' sprints involved in REHIT (i.e.…”

“…The resulting low volume SIT protocol (termed 'reduced-exertion high-intensity interval training'; REHIT) consists of two 20-s 'all-out' sprints within a 10-min otherwise low-intensity exercise session, including warm-up, recovery between sprints and cooldown [26]. We have demonstrated improvements in key cardiometabolic biomarkers with REHIT, including V O 2 max [26][27][28][29], insulin sensitivity and glycaemic control [26,30] and blood pressure [31]. Importantly, REHIT is genuinely time-efficient (2 x~10-min per week) and the low number of sprint repetitions required means it is less likely that participants will experience negative affective responses during exercise [32].…”

Acute and Chronic Effects of Exercise on Continuous Glucose Monitoring Outcomes in Type 2 Diabetes: A Meta-Analysis

“…Several studies included in our meta-analysis did directly compare the effect of different exercise intensities. Some compared continuous exercise to different forms of higher intensity interval training (45,49,54,73), one compared low vs. moderate intensity continuous exercise (48), and one compared different intensities of resistance exercise (40). As in the subgroup analyses from our meta-analysis, no clear pattern emerged when examining these studies individually.…”

Low-volume high-intensity interval training improves cardiometabolic health, work ability and well-being in severely obese individuals: a randomized-controlled trial sub-study

“…However, in contrast, we have previously observed significant reductions in LDL-C levels following 8 weeks of our low-volume HIIT in normal-weight participants [ 29 ]. Moreover, two other studies applying brief “all-out” sprint interval training protocols in sedentary individuals [ 54 ] and type 2 diabetes patients [ 60 ] observed positive glycemic effects despite a substantially lower exercise volume and time commitment than traditional MICT. Since most of the previous studies have included normal-weight, overweight and moderately obese individuals, it might be conceivable that the insufficient improvements in blood lipid profiles and glycemic control observed in the present study may be due to pre-existing less favorable metabolic conditions in our severely obese participants.…”