Effects of hydration state on plasma testosterone, cortisol and catecholamine concentrations before and during mild exercise at elevated temperature.
This investigation examined the influence of pre-exercise hydration status, and water intake during low intensity exercise (5.6 km.h-1 at 5% gradient) in the heat (33 degrees C), on plasma testosterone (TEST), cortisol (CORT), adrenaline (A), and noradrenaline (NA) concentrations at baseline (BL), pre-exercise (PRE), and immediately (IP), 24 h (24 P), and 48 h postexercise (48 P). Ten active men participated in four experimental treatments. These treatments differed in pre-exercise hydration status [euhydrated or hypohydrated (HY, -3.8 (SD 0.7)% body mass)] and water intake during exercise (water ad libitum or no water intake during exercise, NW). There were no significant changes in TEST, CORT, or A concentrations with time (BL, PRE, IP, 24 P, and 48 P), or among treatments. However, significant increases from BL and PRE plasma NA concentrations were observed at IP during all four treatment conditions. In addition, HY+NW resulted in significantly higher plasma NA concentrations at IP compared to all other treatments. These results suggest that moderate levels of hypohydration during prolonged, low intensity exercise in the heat do not influence plasma TEST, CORT, or A concentrations. However, plasma NA appears to respond in a sensitive manner to these hydration and exercise stresses.
Department of Sport, Leisure and Exercise Sciences, University of Connecticut, Storrs 06269.
J R
JR
Hoffman
C M
CM
Maresh
L E
LE
Armstrong
C L
CL
Gabaree
M F
MF
Bergeron
R W
RW
Kenefick
J W
JW
Castellani
L E
LE
Ahlquist
A
A
Ward
D000328:Adult; D001831:Body Temperature; D002395:Catecholamines / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D003681:Dehydration / Q000503:physiopathology; D015444:Exercise; D006339:Heart Rate; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D010783:Photometry; D013739:Testosterone / Q000097:blood*; D014882:Water-Electrolyte Balance
D002395:Catecholamines; D013739:Testosterone; D006854:Hydrocortisone