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DOI: 10.1055/s-0029-1234056
© Georg Thieme Verlag KG Stuttgart · New York
Sodium Balance During U. S. Football Training in the Heat: Cramp-Prone vs. Reference Players
Publikationsverlauf
accepted after revision June 18, 2009
Publikationsdatum:
23. September 2009 (online)
![](https://www.thieme-connect.de/media/sportsmed/200911/lookinside/thumbnails/10.1055-s-0029-1234056-1.jpg)
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°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.
Key words
sweat rate - exercise - heat cramps - dehydration - fluid intake - electrolytes
References
- 1 Adrogue HJ, Madias NE. Hyponatremia. N Engl J Med. 2009; 342 1581-1589
- 2 Almond CS, Shin AY, Fortescue EB, Mannix RC, Wypij D, Binstadt BA, Duncan CN, Olson DP, Salerno AE, Newburger JW, Greenes DS. Hyponatremia among runners in the Boston Marathon. N Engl J Med. 2005; 352 1550-1556
- 3 Baker LB, Lang JA, Kenney WL. Change in body mass accurately and reliably predicts change in body water after endurance exercise. Eur J Appl Physiol. 2009; 105 959-967
- 4 Baker LB, Lang JA, Kenney WL. Quantitative analysis of serum sodium concentration after prolonged running in the heat. J Appl Physiol. 2008; 105 91-99
- 5 Bergeron MF. Muscle cramps during exercise – Is it fatigue or electrolyte deficit?. Curr Sports Med Rep. 2008; 7 S50-S55
- 6 Bergeron MF. Heat cramps during tennis: a case report. Int J Sport Nutr. 1996; 6 62-68
- 7 Binkley HM, Beckett J, Casa DJ, Kleiner DM, Plummer PE. National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses. J Athl Train. 2002; 37 329-343
-
8 Cohen J.
Statistical Power Analysis for the Behavioral Sciences . Hillsdale, New Jersey: Lawrence Erlbaum Associates 1988 -
9 Cohen JJ, Kassirer JP. Acid-base metabolism. In: Maxwell MH, Kleeman CR (eds)
Clinical Disorders of Fluid and Electrolyte Metabolism . New York: McGraw-Hill Book Company 1980: 181-232 - 10 Dill DB, Costill DL. Calculation of percentage changes in volumes of blood, plasma, and red cells in dehydration. J Appl Physiol. 1974; 17 247-248
- 11 Dimeff RJ. Seizure disorder in a professional American football player. Curr Sports Med Rep. 2006; 5 173-176
- 12 Eichner ER. Treatment of suspected heat illness. Int J Sports Med. 1998; 19 S150-S153
- 13 Fowkes Godek S, Bartolozzi AR, Godek JJ. Sweat rate and fluid turnover in American football players compared to runners in a hot humid environment. Br J Sports Med. 2004; 39 205-211
- 14 Herfel R, Stone CK, Koury SI, Blake JJ. Latrogenic acute hyponatraemia in a college athlete. Br J Sports Med. 1998; 257-258
- 15 Hew-Butler T, Almond C, Ayus JC, Dugas J, Meeuwisse W, Noakes T, Reid S, Siegel A, Speedy D, Stuempfle K, Verbalis J, Weschler L. Consensus statement of the 1st International Exercise-Associated Hyponatremia Consensus Development Conference, Cape Town, South Africa 2005. Clin J Sport Med. 2005; 15 208-213
- 16 Jacobson BH, Ransone J, Vardiman P. Comparison of fluid weight loss between heat related illness episodes and non-episodes in football players. Int Sports J. 2001; 5 95-100
- 17 Jung AP, Bishop PA, Al-Nawwas A, Dale RB. Influence of hydration and electrolyte supplementation on incidence and time to onset of exercise-associated muscle cramps. J Athl Train. 2005; 40 71-75
- 18 Kulka TJ, Kenney WL. Heat balance limits in football uniforms. Physician Sports Med. 2002; 30 29-39
- 19 Kurtz I, Nguyen MK. A simple quantitative approach to analyzing the generation of dysnatremias. Clin Exp Nephrol. 2003; 7 144
- 20 Maughan RJ, Shirreffs SM, Leiper JB. Errors in the estimation of hydration status from changes in body mass. J Sports Sci. 2007; 25 797-804
- 21 Montain SJ, Cheuvront SN, Lukaski HC. Sweat mineral-element responses during 7 h of exercise-heat stress. Int J Sport Nutr Exerc Metab. 2007; 17 574-582
- 22 Montain SJ, Cheuvront SN, Sawka MN. Exercise associated hyponatremia: quantitative analysis to understand the aetiology. Brit J Sports Med. 2006; 40 98-106
- 23 Noakes TD, Sharwood K, Speedy D, Hew T, Reid S, Dugas J, Almond C, Wharam P, Weschler L. Three independent biological mechanisms cause exercise-associated hyponatremia: evidence from 2 135 weighed competitive athletic performances. Proc Natl Acad Sci U S A. 2005; 20; 102 18550-18555
- 24 Patterson MJ, Galloway SDR, Nimmo MA. Variations in regional sweat composition in normal human males. Exper Physiol. 2000; 85 869-875
- 25 Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. Exercise and fluid replacement. Med Sci Sports Exerc. 2007; 39 377-390
- 26 Schwellnus MP, Derman EW, Noakes TD. Aetiology of skeletal muscle cramps during exercise: A novel hypothesis. J Sport Sci. 1997; 15 277-285
- 27 Shirreffs SM, Maughan RJ. Whole body sweat collection in humans improved method with preliminary data on electrolyte content. J Appl Physiol. 1997; 83 336-341
- 28 Speedy DP, Noakes TD, Rogers IR, Thompson J, Campbell R, Kuttner A, Boswell DR, Wright S, Hamlin M. Hyponatremia in ultradistance triathletes. Med Sci Sports Exerc. 1999; 31 809-815
- 29 Stofan JR, Osterberg KL, Horswill CA, Lacambra M, Eichner ER, Anderson SA, Murray R. Daily fluid turnover during preseason training in U. S. college football. Int J Sport Nutr Exerc Metab. 2007; 17 340-351
- 30 Stofan JR, Zachwieja JJ, Horswill CA, Horn MK, Osterberg K, Murray R. Assessment of sweat electrolyte losses in humans during exercise: whole body versus regional measurement. FASEB J. 2002; A1141
- 31 Stofan JR, Zachwieja JJ, Horswill CA, Murray R, Anderson S, Eichner ER. Sweat and sodium losses in NCAA football players: A precursor to heat cramps?. Int J Sport Nutr Exerc Metab. 2005; 15 641-652
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