title: Responses of obese and lean girls exercising under heat and thermoneutral conditions.
abstract: OBJECTIVE
  To compare thermoregulatory and perceptual responses between lean and obese girls during and after exercise under heat (HC) and thermoneutral (TC) conditions.
  
  
  METHODS
  In a randomized order, 27 girls (14 lean [16.6 ± 6.7% fat and 9.1 ± 1.3 years] and 13 obese [41.3 ± 6.7% fat and 9.4 ± 1.1 years]) cycled 30 minutes at ~55% peak oxygen uptake in 2 sessions, which only differed in the thermal conditions (35 °C and 40% relative humidity vs 24 °C and 50% relative humidity).
  
  
  RESULTS
  Initial rectal temperature (T(re)) was higher in obese versus lean during HC (37.5 ± 0.3 °C vs 37.3 ± 0.3 °C, P = .03) and TC (37.6 ± 0.3 °C vs 37.3 ± 0.2 °C; P = .03) sessions. During cycling, Tre remained higher in the obese, but the rate of increase was greater in the lean. This change occurred mainly in the HC, when final Tre of the lean surpassed that of the obese (37.8 ± 0.2 vs 38.0 ± 0.2 °C, P = .04). Sweat volume (in mL · m(-2)) was similar between lean and obese in the HC (167 ± 119 and 120 ± 145) and TC (200 ± 196 vs 72 ± 20). Heart rate, rate of perceived exertion, and thermal sensation were similar between groups, independent of the thermal condition. Cycling in HC produced decreased thermal comfort (P = .009) and increased irritation (P = .02) within the lean girls.
  
  
  CONCLUSIONS
  Thermoregulatory and perceptual responses of prepubescent obese girls during 30 minutes of cycling at a similar relative intensity do not seem to be impaired when comparing with a lean group either in TC or HC.
authors.affiliation: Graduate Program in Human Movement Science, School of Physical Education, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil. gabitomedi@yahoo.com.br
authors.forename: Gabriela Tomedi
authors.initials: GT
authors.lastname: Leites
authors.forename: Paulo Lague
authors.initials: PL
authors.lastname: Sehl
authors.forename: Giovani Dos Santos
authors.initials: Gdos S
authors.lastname: Cunha
authors.forename: Adriano
authors.initials: A
authors.lastname: Detoni Filho
authors.forename: Flavia
authors.initials: F
authors.lastname: Meyer
mesh_terms: D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology*; D002648:Child; D015444:Exercise / Q000502:physiology*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D009765:Obesity / Q000503:physiopathology*; D010101:Oxygen Consumption; D013851:Thinness / Q000503:physiopathology*