Effect of exercise-heat acclimation on cardiac autonomic modulation in type 2 diabetes: a pilot study.

ABSTRACT

The effects of exercise-heat acclimation on heart rate variability (HRV) in individuals with type 2 diabetes (T2D) remains unclear. We assessed electrocardiogram recordings during exercise-heat stress in middle-aged-to-older individuals (50-70 years) with (n = 6) and without (control; n = 8;) T2D, before and after 7 days of exercise-heat acclimation. Exercising heart rate was reduced (control, -9 ± 5 bpm; T2D, -14 ± 9 bpm) yet HRV was not significantly different. Given the negative correlations between diminished HRV and cardiac risk observed in the scientific literature, further research is warranted. Novelty Our observations indicate that 7 days exercise-heat acclimation may not effectively attenuate the deviation toward reduced overall HRV and unfavourable cardiac autonomic modulation in individuals with T2D.