Passive heat exposure (e.g., sauna or hot‑water immersion) induces cardiovascular and metabolic responses comparable to moderate aerobic exercise, and is associated with meaningful long‑term health benefits: frequent sauna use shows dose‑dependent reductions in cardiovascular and all‑cause mortality in longitudinal cohorts, while near‑daily hot‑tub bathing is linked to lower cardiovascular disease risk. These benefits are underpinned by exercise‑like adaptations in vascular function, blood pressure, and metabolic regulation (i.e. insulin sensitivity and glucose homeostasis). However, passive heat lacks the mechanical and neuromuscular stimuli required for functional adaptation (at least in healthy older adults), creating a disconnect between internal physiological strain and perceived exercise. Our work addresses this by sensing real‑time physiological responses to heat and translating them into intuitive exercise equivalents, with the aim of improving engagement, personalisation, and cardiometabolic outcomes.
In the News and Media:
- https://www.diabetes.co.uk/news/2024/dec/people-with-type-2-diabetes-can-benefit-from-hot-tub-therapy.html
- https://www.independent.co.uk/life-style/health-and-families/health-study-hot-tub-portsmouth-b2625737.html
- https://www.thesun.co.uk/health/32337121/hot-tub-improves-heart-health-diabetes-study/
- https://www.mirror.co.uk/news/health/hot-tub-volunteers-wanted-scientists-33843326
Relevant Publications
- James, T. J., Corbett, J., Cummings, M., Allard, S., Young, J. S., Towse, J., … & Shepherd, A. I. (2021). Timing of acute passive heating on glucose tolerance and blood pressure in people with type 2 diabetes: A randomized, balanced crossover, control trial. Journal of Applied Physiology. DOI: https://doi.org/10.1152/japplphysiol.00747.2020
- James, T. J., Corbett, J., Cummings, M., Allard, S., Bailey, S. J., Eglin, C., … & Shepherd, A. I. (2024). The effect of repeated hot water immersion on vascular function, blood pressure and central haemodynamics in individuals with type 2 diabetes mellitus. Journal of Thermal Biology, 126, 104017. DOI: https://doi.org/10.1016/j.jtherbio.2024.104017
- James, T. J., Corbett, J., Cummings, M., Allard, S., Shute, J. K., Belcher, H., … & Shepherd, A. I. (2023). The effect of repeated hot water immersion on insulin sensitivity, heat shock protein 70, and inflammation in individuals with type 2 diabetes mellitus. American Journal of Physiology-Endocrinology and Metabolism. DOI: https://doi.org/10.1152/ajpendo.00222.2023
- Piccolo, D. D., Corbett, J., Costello, J. T., Williams, T. B., James, T. J., Shute, J. K., … & Shepherd, A. I. (2026). Effect of repeated hot water immersion on cognitive performance, cerebrovascular function, sleep and biomarkers of neurodegeneration in older adults. Experimental physiology. DOI: https://doi.org/10.1113/EP093500
- Piccolo, D. D., Corbett, J., Exell, T. A., Moore, J. M., Wright, A., Alnajjar, M. G., … & Shepherd, A. I. (2026). Effect of repeated hot water immersion on muscle strength, power, function and physical activity in healthy older adults: A randomised crossover trial. Experimental Physiology. DOI: https://doi.org/10.1113/EP093501