Sodium balance during U. S. football training in the heat: cramp-prone vs. reference players.
Int J Sports Med
; 30(11): 789-94, 2009 Nov.
Article
in En
| MEDLINE
| ID: mdl-19777422
ABSTRACT
U. S. football players with a history of heat cramps were evaluated for the effect of physical training, sodium intake, and loss of sweat sodium on whole blood sodium concentration (BNa). Athletes (n=14 males, 24+/-1 y) were recruited and studied based on medical history, age, and position. The reference group (R, n=8 without a cramping history) and cramp-prone group (C, n=6, history of whole-body cramps associated with extensive sweat loss during exercise in the heat) were measured for body mass and BNa (ISTAT) before and after team training of 2.2 h in hot conditions (WBGT=29-32 degrees C). Intake and loss of fluid and sodium were also measured to determine respective acute balance. In R, BNa was stable pre- to post-training (138.9+/-1.8 to 139.0+/-2.0 mmol/L) while it tended to decline in C (137.8+/-2.3 to 135.7+/-4.9 mmol/L), and three subjects in C had BNa values below 135 mmol/L (131.7+/-2.9 mmol/L). C consumed a greater percentage of total fluid as water (p<0.05). Mean sweat sodium concentration was (52.6+/-29.2 mmol/L for C and 38.3+/-18.3 mmol/L for R (p>0.05). Compared to R, C tended to experience a decline in BNa and greater acute sodium imbalance. These changes may place cramp-prone players at greater risks for developing acute sodium deficits during training.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sodium
/
Heat Stress Disorders
/
Football
/
Muscle Cramp
Type of study:
Observational_studies
/
Risk_factors_studies
Limits:
Adult
/
Humans
/
Male
Country/Region as subject:
America do norte
Language:
En
Journal:
Int J Sports Med
Year:
2009
Document type:
Article