Summary: In a single-centre randomised trial of 57 sedentary adults with type 2 diabetes, the acute effects of one session of high-intensity interval training (HIIT) were compared with moderate-intensity continuous exercise (MOD). Brachial flow-mediated dilation rose from 9.3% to 20.05% after HIIT (p<0.01) and post-exercise glucose fell from 189 to 149 mg/dL (p<0.01); endothelial improvement was more pronounced with HIIT, while both modalities lowered glucose. These are immediate, single-session effects, not chronic training outcomes.
PICO Summary
| Element | Detail |
|---|---|
| Population | 57 sedentary adults with type 2 diabetes (39 women, 18 men); single-centre randomised controlled trial, Brazil. |
| Intervention | One session of HIIT: 10 sprints of 30 s at 85 to 100% of maximum heart rate, with 1-minute active pauses (one arm of the randomised cohort; approximately half of the 57 participants). |
| Comparison | One session of moderate-intensity continuous exercise (MOD) at 60 to 70% of maximum heart rate for 30 minutes (other arm; approximately half of the cohort). |
| Outcome | Brachial flow-mediated dilation (%FMD) increased from 9.3 ± 5.3% to 20.05 ± 9.3% after HIIT (p<0.01); post-exercise blood glucose fell from 189 [106 to 335] to 149 [70 to 448] mg/dL after HIIT (p<0.01). Endothelial improvement was more pronounced with HIIT than MOD; both modalities improved glycaemia. No 95% confidence intervals, ARR or NNT were reported, and no chronic or HbA1c outcomes were assessed. |
Acute HIIT vs moderate exercise on endothelial function
RCT · type 2 diabetes · single session
One HIIT session acutely raised flow-mediated dilation more than moderate exercise, and both lowered post-exercise glucose. Acute single-session signal only, with no chronic or HbA1c outcomes.
Expert Commentary
This randomised trial provides a modest, mechanistically interesting signal: a single bout of high-intensity interval exercise acutely improved endothelial function more than moderate continuous exercise in sedentary adults with type 2 diabetes, and both lowered glucose measured immediately afterwards. The verdict is that the acute endothelial advantage of HIIT is plausibly real but preliminary, and it should not be read as evidence of sustained cardiovascular protection or durable glycaemic control. The most consequential limitation is the acute, single-session design: flow-mediated dilation and glucose were measured only once, immediately after exercise, so nothing can be inferred about whether repeated sessions translate into lasting vascular or metabolic benefit. The small sample of 57 split across two arms, the single-centre setting, and the absence of confidence intervals, HbA1c or longer-term endpoints further constrain interpretation. No industry or manufacturer sponsorship was evident, and the effect sizes, while large for an acute endothelial response, are not implausible for vigorous exercise. Can I use this with my patients? Cautiously yes, for selected, appropriately screened patients who can safely tolerate vigorous interval work, as one more reason to encourage exercise, but not as a basis for claiming HIIT controls diabetes. Future work should test whether these acute gains persist with structured training and hard outcomes.
References
Costa-Arruda RMD, Padovani C, Correia M, Consolim-Colombo F, Phillips S, Ritti-Dias R, Sampaio LMM. The impact of two different aerobic exercise intensities on cardiometabolic parameters in type 2 diabetic patients: A randomized trial. J Bodyw Mov Ther. 2024;42:153-161. doi:10.1016/j.jbmt.2024.12.013