title: Effects of Precooling on 30-km Cycling Performance and Pacing in Hot and Temperate Environments.
abstract: This study examined the effects of precooling on performance and pacing during 30-km cycling exercise in hot and temperate environments. 8 trained male cyclists performed 4 trials involving either cooling (PRECTEMPand PRECHOT) or no-cooling interventions (TEMP and HOT) prior to a 30-km self-paced cycling exercise in either a hot (35°C, 68% relative humidity) or temperate environment (24°C, 68% relative humidity). Exercise time was longer in HOT (60.62±3.47 min) than in TEMP (58.28±3.30 min;P<0.001), and precooling attenuated this thermal strain performance impairment (PRECHOT58.28±3.30 min;P=0.048), but it was still impaired compared with TEMP (P=0.02). Exercise performance in PRECTEMP(54.58±4.35 min) was no different from TEMP. Initial power output was sustained until the end of the exercise in both TEMP and PRECTEMP, but was reduced from the 12thkm until the end of the trial in HOT (P<0.05). This reduction was delayed by precooling because power output was reduced only after the 20thkm during PRECHOT(P<0.05). Heart rate was similar in all conditions throughout almost the entire exercise, suggesting the maintenance of similar relative intensities. In conclusion, precooling was effective in attenuating, but not completely reversing thermal strain performance impairment and offered no ergogenic effect in the temperate environment.
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Maia-Lima
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Guilherme Passos
authors.initials: GP
authors.lastname: Ramos
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Michele Macedo
authors.initials: MM
authors.lastname: Moraes
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Diogo Antônio Soares
authors.initials: DA
authors.lastname: Pacheco
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Gustavo Guimarães Aguiar
authors.initials: GG
authors.lastname: de Oliveira
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Cristiano Lino Monteiro
authors.initials: CL
authors.lastname: de Barros
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Luciano Sales
authors.initials: LS
authors.lastname: Prado
authors.affiliation: Laboratory of Exercise Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Emerson Silami
authors.initials: ES
authors.lastname: Garcia
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D001831:Body Temperature; D018592:Cross-Over Studies; D004326:Drinking; D005080:Exercise Test; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D013546:Sweating