The addition of carbohydrate and sodium to sport drinks has been recommended to enhance fluid intake and absorption and to delay fatigue. Other electrolytes (E) which are lost through sweating are also commonly added. However, too many E may lead to increased serum E and osmolality levels, which may negatively influence thermoregulation, depress sweating, and cause gastrointestinal distress. On the other hand, drinking large amounts of plain water to compensate sweat loss may induce hyponatremia. Therefore, literature describing sweat E losses was examined in order to estimate average whole-body E loss and to determine an upper limit for replacement of E with sport drinks. Mean E loss was determined from 13 studies, with +1 SD resulting in a hypothetical range for E losses. Correction for net absorption resulted in an upper limit of electrolyte replacement. It is suggested that the E levels in sport rehydration drinks should not exceed the upper limit of the range given.
Fred Brouns, Wim Saris and Heinz Schneider
Michelle A. Cleary and Douglas J. Casa
Michelle A. Cleary and Douglas J. Casa
Martin J. Turner and Alberto P. Avolio
International guidelines suggest limiting sodium intake to 86–100 mmol/day, but average intake exceeds 150 mmol/day. Participants in physical activities are, however, advised to increase sodium intake before, during and after exercise to ensure euhydration, replace sodium lost in sweat, speed rehydration and maintain performance. A similar range of health benefits is attributable to exercise and to reduction in sodium intake, including reductions in blood pressure (BP) and the increase of BP with age, reduced risk of stroke and other cardiovascular diseases, and reduced risk of osteoporosis and dementia. Sweat typically contains 40–60 mmol/L of sodium, leading to approximately 20–90 mmol of sodium lost in one exercise session with sweat rates of 0.5–1.5 L/h. Reductions in sodium intake of 20–90 mmol/day have been associated with substantial health benefits. Homeostatic systems reduce sweat sodium as low as 3–10 mmol/L to prevent excessive sodium loss. “Salty sweaters” may be individuals with high sodium intake who perpetuate their “salty sweat” condition by continual replacement of sodium excreted in sweat. Studies of prolonged high intensity exercise in hot environments suggest that sodium supplementation is not necessary to prevent hyponatremia during exercise lasting up to 6 hr. We examine the novel hypothesis that sodium excreted in sweat during physical activity offsets a significant fraction of excess dietary sodium, and hence may contribute part of the health benefits of exercise. Replacing sodium lost in sweat during exercise may improve physical performance, but may attenuate the long-term health benefits of exercise.
Marcus B. Stone, Jeffrey E. Edwards, Catherine L. Stemmans, Christopher D. Ingersoll, Riann M. Palmieri and B. Andrew Krause
Despite recent evidence to suggest that exercise-associated muscle cramps (EAMC) might be primarily of neuromuscular origin, the authors surmise that most information available to certified athletic trainers (ATCs) emphasizes the role of dehydration and electrolyte imbalance in EAMC.
To investigate ATCs' perceptions of EAMC.
7-question, Web-based, descriptive, cross-sectional survey.
Main Outcome Measures:
Responses to 7 questions regarding the cause, treatment, and prevention of EAMC.
Responders indicated humidity, temperature, training, dehydration, and electrolyte imbalance as causative factors of EAMC. Fluid replacement and stretching the involved muscle were identified as very successful in treating and preventing EAMC. Proper nutrition and electrolyte replacement were also perceived as extremely successful prevention strategies.
ATCs' perceptions of the cause, treatment, and prevention of EAMC are primarily centered on dehydration and electrolyte imbalance. Other prominent ideas concerning EAMC should be implemented in athletic training education.
Lindsay B. Baker, Kelly A. Barnes, Bridget C. Sopeña, Ryan P. Nuccio, Adam J. Reimel and Corey T. Ungaro
,104 versus 1,352 mg/hr of Na + lost during exercise. Fluid/electrolyte replacement strategies for athletes ( Sawka et al., 2007 ; Thomas et al., 2016 ) likely will not differ significantly between these two scenarios. When high accuracy is required, such as during laboratory research and electrolyte
Dawn M. Emerson, Toni M. Torres-McGehee, Susan W. Yeargin, Kyle Dolan and Kelcey K. deWeber
had adequate access), may choose to provide more dietary recommendations, or they do not perceive issues within their team(s) that requires supplements. Because ice hockey athletes are less likely to drink sports drinks during practice, 2 , 4 electrolyte replacement may be warranted for those at risk
Manuel D. Quinones and Peter W.R. Lemon
guidelines ( American College of Sports Medicine, 2017 ). The electrolyte concentration in both beverages was the same and controlled using a noncaloric flavored electrolyte replacement powder (UCAN Hydrate ® , Woodbridge, CT) that contained 94 mg/L of magnesium, 282 mg/L of chloride, 563 mg/L of sodium, 188
Jennifer Sygo, Alicia Kendig Glass, Sophie C. Killer and Trent Stellingwerff
more effective in situations of fatigue and could be especially ergogenic in the jumps, as there is no increase in BW due to fluid intake. Does not appear to have any negative side effects. Protocol: Wash mouth out with CHO sports drinks for 5–10 s every 10 min of event or training. c c c c Electrolyte
Philo U. Saunders, Laura A. Garvican-Lewis, Robert F. Chapman and Julien D. Périard
or soft drinks because they have optimal sugar concentrations to maximize the uptake of water by the body. Consuming a combination of fluids and solid foods is also advisable for rehydration and electrolyte replacement. The notion that permissive dehydration or restricted fluid consumption may