Type 2 Diabetes Raises Fall Risk After Exercise in the Heat

Falls are a leading cause of injury in older adults with diabetes, and this study adds an important new dimension to that risk: exercising in the heat may dramatically worsen balance in this population, even when body temperature appears well-regulated.

Researchers at the National University of Singapore recruited 30 middle-aged men — 15 with type 2 diabetes (T2D) and 15 healthy controls — matched for age and fitness. Participants walked for one hour at a moderate intensity in two environments: a cool condition (22°C, 50% humidity) and a warm-humid condition (32°C, 70% humidity). Postural balance was assessed before and after each session using center-of-pressure measurements on both stable and unstable surfaces, alongside grip strength and sit-to-stand tests.

The key finding was striking: men with T2D showed significantly greater postural instability after exercising in the heat, particularly on the unstable surface. Anteroposterior sway, total sway excursion, and mean sway velocity all increased meaningfully in the T2D group under warm conditions — with effect sizes ranging from moderate to large (d = 0.86 to 1.49). Crucially, thermoregulatory markers — core temperature, skin temperature, heart rate, and sweat rate — were comparable between groups, suggesting the balance deficit is not simply a consequence of overheating.

The authors propose that T2D-associated peripheral neuropathy and altered hemodynamics may impair the sensory and vascular systems needed to maintain balance during and after heat stress. Vibrotactile sensitivity in the feet, often reduced in diabetic neuropathy, is critical for postural control on unstable surfaces.

For clinicians and patients, this research highlights a largely overlooked fall risk scenario: outdoor or gym exercise in warm weather for people with T2D. Monitoring balance post-exercise and avoiding unstable surfaces in hot conditions may be prudent precautions.