title: Rain influences the physiological and metabolic responses to exercise in hot conditions.
abstract: Outdoor exercise often proceeds in rainy conditions. However, the cooling effects of rain on human physiological responses have not been systematically studied in hot conditions. The present study determined physiological and metabolic responses using a climatic chamber that can precisely simulate hot, rainy conditions. Eleven healthy men ran on a treadmill at an intensity of 70% VO2max for 30 min in the climatic chamber at an ambient temperature of 33°C in the presence (RAIN) or absence (CON) of 30 mm · h(-1) of precipitation and a headwind equal to the running velocity of 3.15 ± 0.19 m · s(-1). Oesophageal temperature, mean skin temperature, heart rate, rating of perceived exertion, blood parameters, volume of expired air and sweat loss were measured. Oesophageal and mean skin temperatures were significantly lower from 5 to 30 min, and heart rate was significantly lower from 20 to 30 min in RAIN than in CON (P < 0.05 for all). Plasma lactate and epinephrine concentrations (30 min) and sweat loss were significantly lower (P < 0.05) in RAIN compared with CON. Rain appears to influence physiological and metabolic responses to exercise in heat such that heat-induced strain might be reduced.
authors.affiliation: a University Educational Center, Nihon Fukushi University , Mihama-cho , Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Ito
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Yamashita
authors.forename: Eiko
authors.initials: E
authors.lastname: Suzuki
authors.forename: Takaaki
authors.initials: T
authors.lastname: Matsumoto
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D001833:Body Temperature Regulation; D004837:Epinephrine / Q000097:blood; D004947:Esophagus / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010465:Perception; D005082:Physical Exertion; D011891:Rain; D012420:Running / Q000502:physiology*; D012881:Skin Temperature; D013546:Sweating; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D014280:Triglycerides; D019344:Lactic Acid; D009638:Norepinephrine; D004837:Epinephrine
keywords: heart rate; hyperthermia; lactate; rain; thermoregulation