Alison Millyard , Henry B. Ogden , Sally P. Waterworth , David B. Pyne , Joseph D. Layden , Saul R. Bloxham
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引用次数: 0
Abstract
Older adults are vulnerable to heat-related morbidity and mortality due to reduced thermoregulatory function associated with aging. The aim of this study was to examine the relationship between age and thermoregulatory behaviour during walking exercise in Control (22 °C; 40% relative humidity [RH]) and Hot (35 °C, 40% RH) conditions. Thirty-six healthy males (age 46 ± 20 (range 19–86) years; stature 177 ± 7 cm; body mass 75.7 ± 11.3 kg; BMI 24.2 ± 2.9 kg m−2; Ʃskinfolds 33.3 ± 10.5 mm; mean ± SD) each completed two experimental trials, one in Control and one in Hot conditions. Each trial consisted of three bouts of 10 min walking at a rating of perceived exertion (RPE) of 13, interspersed with 5 min of seated rest. Thermoregulatory behaviour was assessed as the ratio between distance walked in the Control and Hot trials. Participants walked 3.8% less in the Hot (2.63 ± 0.46 km) than in the Control (2.73 ± 0.4 km) condition (t(36) = −2.38, p = 0.023, d = 0.26). Regression analysis demonstrated that age was the primary predictor of thermoregulatory pacing behaviour, explaining 23% of the variance (Std β = −0.475, p = 0.003). Including physical activity levels (PASE) increased the variance accounted to 32% (age Std β = −0.396, p = 0.011; PASE Std β = 0.319, p = 0.038). In conclusion, thermoregulatory pacing behaviour was impaired with increased age and reduced physical activity when undertaking walking exercise at a perceived exertion of ‘somewhat hard’ in hot ambient conditions.
期刊介绍:
The Journal of Thermal Biology publishes articles that advance our knowledge on the ways and mechanisms through which temperature affects man and animals. This includes studies of their responses to these effects and on the ecological consequences. Directly relevant to this theme are:
• The mechanisms of thermal limitation, heat and cold injury, and the resistance of organisms to extremes of temperature
• The mechanisms involved in acclimation, acclimatization and evolutionary adaptation to temperature
• Mechanisms underlying the patterns of hibernation, torpor, dormancy, aestivation and diapause
• Effects of temperature on reproduction and development, growth, ageing and life-span
• Studies on modelling heat transfer between organisms and their environment
• The contributions of temperature to effects of climate change on animal species and man
• Studies of conservation biology and physiology related to temperature
• Behavioural and physiological regulation of body temperature including its pathophysiology and fever
• Medical applications of hypo- and hyperthermia
Article types:
• Original articles
• Review articles