title: Beneficial Effects of Cooling during Constant Power Non-steady State Cycling.
abstract: This study compared the effects of cooling on the energetic and associated physiological and perceptual responses to constant power, non-steady state cycling. Twelve males cycled at their lactate threshold power for 60 min or until exhaustion under 3 conditions: wearing a cooling vest and sleeves (COOL), a synthetic shirt embedded with an active particle technology claimed to facilitate evaporative heat loss (EVAP), and a standard synthetic shirt (CON). When adjusted for time, the increase in gastrointestinal temperature from baseline was reduced during COOL and EVAP compared to CON (1.44±0.45 and 1.52±0.43 vs. 1.66±0.45°C, p<0.05). Sweat rate was reduced during COOL compared to EVAP and CON (1 312±331 vs. 1 525±393 and 1 550±548 mL·h-1, p<0.01). Gross efficiency decreased over time across conditions (p<0.01), but COOL attenuated this decrease by 22% compared to CON (p<0.05). The rating of perceived exertion was reduced during COOL and EVAP compared to CON (p<0.01). In conclusion, cooling using a vest and sleeves or wearing an active particle technology shirt reduced the rise in gastrointestinal temperature and rating of perceived exertion compared to a standard synthetic shirt. Cooling using a vest and sleeves also reduced the decrease in gross efficiency and sweat rate compared to wearing the standard synthetic shirt.
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Homestead
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Ryan
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States.
authors.forename: Jesse A
authors.initials: JA
authors.lastname: Goodrich
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States.
authors.forename: William C
authors.initials: WC
authors.lastname: Byrnes
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001810:Blood Volume; D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology*; D003020:Clothing; D004734:Energy Metabolism; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D005082:Physical Exertion; D013546:Sweating; D013697:Thermosensing; D055815:Young Adult
chemical_list: D019344:Lactic Acid