Daily fluid turnover during preseason training in U.S. college football.
The authors measured 24-h fluid-turnover (FTO) rate during 6 d of preseason training in U.S. college football players. Players, training (T, n = 9, full gear and contact drills) and reference (R, n = 4, conditioning without gear or contact), ingested a deuterium oxide (D(2)O) dose and provided urine samples every 24 h for analysis of D(2)O. During one approximately 2.3-h practice (wet-bulb globe temperature 24.6 degrees C), body-mass change, urine production, and voluntary fluid intake were measured to calculate gross sweat loss (GSL). Average FTO was 10.3 +/- 2.2 L/d for T and 7.0 +/- 1.0 L/d for R. GSL was 3.4 +/- 1.5 L for T and 1.7 +/- 1.3 for R (P > 0.05). By Day 6, body mass decreased significantly in T (-2.4 +/- 1.3 kg, P < 0.05) but not in R (0.38 +/- 0.95 kg). With preseason training under moderate environmental stress, football players had high FTO and sweat rates, which might have contributed to a loss of body mass during preseason football training.
Stofan
John R
JR
Gatorade Sports Science Institute, Barrington, IL 60010, USA.
Osterberg
Kris L
KL
Horswill
Craig A
CA
Lacambra
Magie
M
Eichner
E Randy
ER
Anderson
Scott A
SA
Murray
Robert
R
D000328:Adult; D001834:Body Water / Q000378:metabolism*; D001835:Body Weight / Q000502:physiology*; D017666:Deuterium Oxide / Q000652:urine; D004327:Drinking Behavior; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D012621:Seasons; D013546:Sweating / Q000502:physiology*; D016482:Urinalysis
D017666:Deuterium Oxide