TY - JOUR

T1 - Two nights of sleep deprivation with or without energy restriction does not impair the thermal response to cold

AU - Oliver, Samuel J.

AU - Harper Smith, Adam D.

AU - Costa, Ricardo J.S.

AU - Maassen, Norbert

AU - Bilzon, James L.J.

AU - Walsh, Neil P.

N1 - Publisher Copyright: © 2015, Springer-Verlag Berlin Heidelberg.

PY - 2015/10/22

Y1 - 2015/10/22

N2 - Purpose: In persons completing exhaustive daily exercise, sleep and energy restriction have been highlighted as risk factors for hypothermia in cold environments. The present study therefore sought to determine the effect of sleep deprivation (SDEP), with and without energy restriction, on the thermal response to cold. Methods: In a random order, ten recreationally active men (mean ± SD: age 25 ± 6 years, body fat 17 ± 5 %) completed three 53 h trials: a control (CON: 436 min/night sleep), SDEP (0 min sleep), and sleep deprivation and energy restriction (SDEP + ER: 0 min sleep and 10 % daily energy requirements). Exhaustive exercise was completed after 5 and 29 h. After 53 h participants completed a semi-nude seated cold air test (CAT, 0 °C), for 4 h or until rectal core temperature (Tre) reached 36 °C. Results: Two nights of sleep and energy restriction did not impair the thermal response to cold (Tre, CON 36.15 ± 0.20 °C, SDEP 36.30 ± 0.15 °C, SDEP + ER 36.25 ± 0.20 °C, P = 0.25). Rewarming was also similar as indicated by 1 h post-CAT Tre (P = 0.78). In contrast, perceived thermal discomfort during the initial hour of the CAT tended to be greater after SDEP and SDEP + ER (P ≤ 0.1). Conclusion: Sleep and energy restriction, at least as evaluated within this experiment, should be considered minimal risk factors for hypothermia. The greater perception of cold discomfort at the same body temperature suggests that sleep and energy restriction may actually reduce cold injury risk, as people are likely to engage earlier in normal behavioral cold adaptation.

AB - Purpose: In persons completing exhaustive daily exercise, sleep and energy restriction have been highlighted as risk factors for hypothermia in cold environments. The present study therefore sought to determine the effect of sleep deprivation (SDEP), with and without energy restriction, on the thermal response to cold. Methods: In a random order, ten recreationally active men (mean ± SD: age 25 ± 6 years, body fat 17 ± 5 %) completed three 53 h trials: a control (CON: 436 min/night sleep), SDEP (0 min sleep), and sleep deprivation and energy restriction (SDEP + ER: 0 min sleep and 10 % daily energy requirements). Exhaustive exercise was completed after 5 and 29 h. After 53 h participants completed a semi-nude seated cold air test (CAT, 0 °C), for 4 h or until rectal core temperature (Tre) reached 36 °C. Results: Two nights of sleep and energy restriction did not impair the thermal response to cold (Tre, CON 36.15 ± 0.20 °C, SDEP 36.30 ± 0.15 °C, SDEP + ER 36.25 ± 0.20 °C, P = 0.25). Rewarming was also similar as indicated by 1 h post-CAT Tre (P = 0.78). In contrast, perceived thermal discomfort during the initial hour of the CAT tended to be greater after SDEP and SDEP + ER (P ≤ 0.1). Conclusion: Sleep and energy restriction, at least as evaluated within this experiment, should be considered minimal risk factors for hypothermia. The greater perception of cold discomfort at the same body temperature suggests that sleep and energy restriction may actually reduce cold injury risk, as people are likely to engage earlier in normal behavioral cold adaptation.

KW - Cold injury

KW - Hypothermia

KW - Sleep loss

KW - Thermogenesis

KW - Thermoregulation

UR - http://www.scopus.com/inward/record.url?scp=84941878967&partnerID=8YFLogxK

U2 - 10.1007/s00421-015-3184-y

DO - 10.1007/s00421-015-3184-y

M3 - Article

C2 - 25995099

AN - SCOPUS:84941878967

VL - 115

SP - 2059

EP - 2068

JO - European Journal of Applied Physiology

JF - European Journal of Applied Physiology

SN - 1439-6319

IS - 10

ER -