ISSN:
1439-6327
Keywords:
Key words Temperature regulation
;
Esophageal temperature
;
Cutaneous vasodilation
;
Exercise
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We have previously demonstrated a prolonged (65 min or longer) elevated plateau of esophageal temperature (T es ) (0.5–0.6°C above pre-exercise values) in humans following heavy dynamic exercise (70% maximal oxygen consumption, V˙O2max) at a thermoneutral temperature (T a) of 29°C. The elevated T es value was equal to the threshold T es at which active skin vasodilation was initiated during exercise (Thdil). A subsequent observation, i.e., that successive exercise/recovery cycles (performed at progressively increasing pre-exercise T es levels) produced parallel increases of Thdil and the post-exercise T es, further supports a physiological relationship between these two variables. However, since all of these tests have been conducted at the same T a (29°C) and exercise intensity (70% V˙O2max) it is possible that the relationship is limited to a narrow range of T a/exercise intensity conditions. Therefore, five male subjects completed 18 min of treadmill exercise followed by 20 min of recovery in the following T a/exercise intensity conditions: (1) cool with light exercise, T a = 20°C, 45% V˙O2max (CL); (2) temperature with heavy exercise, T a = 24°C, 75% O2 max (TH); (3) warm with heavy exercise, T a = 29°C, 75% V˙O2max (WH); and (4) hot with light exercise, T a = 40°C, 45% V˙O2max (HL). An abrupt decrease in the forearm-to-finger temperature gradient (T fa −T fi) was used to identify the Thdil during exercise. Mean pre-exercise T es values were 36.80, 36.60, 36.72, and 37.20°C for CL, TH, WH, and HL conditions respectively. T es increased during exercise, and end post-exercise fell to stable values of 37.13, 37.19, 37.29, and 37.55°C for CL, TH, WH, and HL trials respectively. Each plateau value was significantly higher than pre-exercise values (P 〈 0.05). Correspondingly, Thdil values (i.e., 37.20, 37.23, 37.37, and 37.48°C for CL, TH, WH, and HL) were comparable to the post-exercise T es values for each condition. The relationship between Thdil and post-exercise T es remained intact in all T a/exercise intensity conditions, providing further evidence that the relationship between these two variables is physiological and not coincidental.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004210050221
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