Exercise heat acclimation and post-exercise hot water immersion improve resting and exercise responses to heat stress in the elderly

Objectives To investigate the efficacy of heat acclimation (HA) in young (YEX) and elderly (EEX) following exercise-HA, utilising post-exercise hot water immersion HA (EHWI). Design Cross-sectional study. Method Twenty-six participants (YEX: n = 11 aged 22 ± 2 years, EEX: 8 68 3 EHWI: 7 73 years) completed two pre-/post-tests, separated by five intervention days. YEX EEX exercised conditions to raise rectal temperature (Trec) ?38.5 °C within 60 min, with this increase maintained for a further min. EHWI 30 min cycling temperate conditions, then HWI (40 °C), followed seated blanket wrap. Pre- post-testing comprised rest, exercise (3.5 W·kg?1 ?prod), six-minute walk test (6MWT), all 35 °C, 50% RH. Results The protocols did not elicit different mean heart rate (HR), Trec, duration Trec ? 38.5 (p > 0.05) between YEX, EEX, groups. Resting peak skin temperature, systolic arterial pressure, perceived exertion thermal sensation decreased, 6MWT distance increased pre- post-HA < 0.05), no difference also demonstrated reduction resting HR 0.05). No change was observed or HR, vascular conductance, sweat rate, comfort any group Conclusions Irrespective age intervention, induced thermoregulatory, perceptual performance improvements. Both exercise-HA (EEX), (EHWI) are considered viable interventions prepare stress.