It’s that time of year again, with official practices starting for many fall sports programs and discussions regarding safe participation in the heat are at the forefront of athletic training. In addition to the important and very serious discussions surrounding the prevention and treatment of heat stroke and related illnesses, hydration and maintaining proper fluid balance are also vital for athletes participating in the heat during pre-season training.
Sodium is the main electrolyte lost in sweat in addition to body water. During conditions that facilitate high sweat rates, Athletic Trainers know that large losses can lead to decreases in plasma volume and cardiac output, as well as the potential to develop hyponatremia. This is why the National Athletic Trainers Association (NATA) position statement on fluid replacement stresses constant ingestion of fluids during exercise in the heat in order to minimize body weight losses to around 2%. The NATA also recommends the addition of 0.3 to 0.7 g/L of salt to hydration beverages in order to offset sodium losses due to sweating (NATA Position Statement on Fluid Replacement).
In addition to hydration during participation, it is of equal importance to educate participants about rehydration and sodium replacement strategies that should continue after the day’s activities have concluded following the NATA’s guidelines. These strategies include achieving full rehydration within 4-6 hours post-activity, which can be accomplished by ingesting fluids up to 150% of total sweat losses. Post-activity replacement strategies must also include sodium in both fluids and as a part of meals. However, the NATA advises that the exact amounts must be individualized to each athlete with special care taken to avoid overdrinking. The full NATA position statement on fluid replacement can be found here: http://www.nata.org/sites/default/files/FluidReplacementsForAthletes.pdf
Athletic Trainers play a critical role in educating athletes about proper hydration strategies – prevention is one of the five major domains of the AT scope of practice. Failure for athletes to fully rehydrate and replace sodium over the course of pre-season training camps can put athletes in the difficult position of constantly trying to get their bodies caught up, which can be prevented with proper guidance on hydration and nutrition. Also, don’t forget about your coaches. They are in the same conditions as the athletes and can also benefit greatly from proper hydration strategies.
Additional information on conditions affecting athletes that participate in the heat can also be found in other position statements from the National Athletic Trainers Association:
- National Athletic Trainers’ Association Position Statement: Preventing Sudden Death in Sports – http://www.nata.org/sites/default/files/Preventing-Sudden-Death-Position-Statement_2.pdf
- National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses – http://www.nata.org/sites/default/files/ExternalHeatIllnesses.pdf
Written By: Mike McKenney, LAT, ATC, NASM-CES