title: A shirt containing multistage phase change material and active cooling components was associated with increased exercise capacity in a hot, humid environment.
abstract: Recent advances in clothing design include the incorporation of phase change materials (PCM) and other active cooling components (ACC) to provide better body heat dissipation. The purpose of this study was to determine the effect of wearing a shirt containing multistage PCM/ACC on exercise capacity at low (5.0), moderate-high (7.5) and extreme (9.0) levels of the physiological strain index (PSI). Fourteen individuals tested two shirts (control vs. cooling) during 45-min of interval running in a hot, humid (35 ± 1 °C; 55 ± 6% RH) environment. The cooling shirt resulted in an 8% improvement in exercise capacity at a PSI of 7.5 (p < 0.05). The observed increase in exercise capacity would likely translate to a significant improvement in exercise performance. More research is needed to determine a best practice approach for the use of cooling clothing as a counter to exercise-induced heat exposure. Practitioner Summary: In this report, we demonstrate that when forced to exercise in a hot, humid environment, an individual's exercise capacity may increase by as much as 8% when wearing a shirt composed of multistage phase change material and active cooling components.
authors.affiliation: a Applied Physiology Laboratory , University of North Texas , Denton , TX , USA.|b Department of Biological Sciences , University of North Texas , Denton , TX , USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: McFarlin
authors.affiliation: a Applied Physiology Laboratory , University of North Texas , Denton , TX , USA.|b Department of Biological Sciences , University of North Texas , Denton , TX , USA.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Henning
authors.affiliation: a Applied Physiology Laboratory , University of North Texas , Denton , TX , USA.|b Department of Biological Sciences , University of North Texas , Denton , TX , USA.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Venable
authors.affiliation: a Applied Physiology Laboratory , University of North Texas , Denton , TX , USA.
authors.forename: Randall R
authors.initials: RR
authors.lastname: Williams
authors.affiliation: a Applied Physiology Laboratory , University of North Texas , Denton , TX , USA.|b Department of Biological Sciences , University of North Texas , Denton , TX , USA.
authors.forename: Jill N
authors.initials: JN
authors.lastname: Best Sampson
mesh_terms: D001833:Body Temperature Regulation / Q000502:physiology; D004781:Environmental Exposure / Q000517:prevention & control*; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D006813:Humidity / Q000009:adverse effects*; D008422:Materials Testing / Q000379:methods*; D017063:Outcome Assessment, Health Care; D011481:Protective Clothing; D012420:Running / Q000502:physiology*
keywords: Core body temperature; exercise performance; extreme environment; thermal comfort