Effectiveness of skin-heating using a water-perfused suit as passive and post-exercise heat acclimation strategies. (October 2020)

• Record Type: Journal Article
• Authors: Ko, Yelin; Kang, Juho; Seol, Seon-Hong; Lee, Joo-Young
• Is Part Of: Journal of thermal biology. Volume 93(2020)
• Publication Date: 2020-10
• Subjects: Heat acclimation -- Water-perfused suit -- Post-exercise heat acclimation -- Passive heat acclimation -- Skin temperature -- Body core temperature; Thermobiology -- Periodicals; Temperature -- Periodicals; Biology -- Periodicals; Thermobiologie -- Périodiques; Thermobiology; Periodicals; 571.46
• DOI: 10.1016/j.jtherbio.2020.102703
• Languages: English
• ISSNs: 0306-4565

Abstract

Abstract: The purpose of the present study was to evaluate the effectiveness of passive and post-exercise heat acclimation strategies through directly heating the skin with a water-perfused suit. Nineteen young males participated in the heat acclimation (HA) protocols for 10 days, which were conducted at an air temperature of 33 o C with 60%RH. The exercise-only condition (N = 6) conducted 1-h treadmill walking (6 km·h -1 ) followed by 1-h rest. The post-exercise passive-heating condition (N = 6) wore the suit (inflow water temperature 44.2 o C) for 1-h after 1-h walking. The passive-heating condition (N = 7) donned the suit for 2 h. Heat tolerance tests (leg immersion in 42 o C water for 60 min) were conducted before and after the training to evaluate changes due to the 10-day intervention. Reflecting that suit-wearing for 10 days as both passive and post-exercise HA strategies can effectively induce adaptive changes, significant interaction effects appeared in: increase or decrease in mean skin temperature ( P < 0.05) and elevation in whole-body sweat rate ( P < 0.05). Reduction in rectal temperature ( P < 0.05) and blood pressure ( P < 0.05) were found most prominently in the passive-heating condition. These results indicate that this new method of heat acclimation training, donning a skin-heating water-perfused suit, can generate thermoregulatory benefits. The passive HA intervention could be applied to individuals for whom doing exercise regularly are not feasible. Highlights: Wearing liquid warming garment in a hot and humid environment for 10 days can be a passive heat acclimation (HA) strategy. In order to sufficient HA by the passive HA strategy, at least 2-h heating per day with about 44 o C water temperature is needed. The passive HA intervention could be applied to individuals for whom doing exercise regularly are not feasible.