Pass the Sodium (Na) Please

Table full of water bottles
June 28, 2022

George Epley


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As summer brings warmer temperatures to many parts of North America, sodium plays a vital role in endurance athletes’ homeostatic balance.  The research I am sharing is an important consideration for your summer triathlon training and racing as hydration can have a huge impact on your performance.

The American College of Sports Medicine recommends that endurance athletes consume 0.5 to 0.7g of sodium in each liter of sports drink, and fluid intake is adjusted to an individual’s sweet rate (Nieman, 2007).

During training and racing, the athlete’s fluid intake schedule should match fluid loss with a goal of less than two percent of body weight (Desmond, 2006). The athlete should be aware of their body’s average hourly sweat rate during exercise and consume fluids and sodium to replace what was lost each hour, and fluid intake should occur in regular intervals, not all at once. (Desmond, 2006).

Ideally, the amount of sodium consumed during exercise should match the rate of sodium lost through sweat (Veniamakis, Kaplanis, Voulgaris, & Nikolaidis, 2022). The practice of consuming large amounts of fluids containing sodium hours before a race to compensate for sweat loss is an incorrect guideline for fluid intake before an event and, when carried to the extreme, can lead to severe consequences associated with hyponatremia (Veniamakis, Kaplanis, Voulgaris, & Nikolaidis, 2022).  Exercise-induced hyponatremia is associated with low blood sodium concentration during or immediately after physical activity (Hew-Butler, Loi, Pani, Rosner, 2017). 

Proper sodium levels ensure that sufficient blood volume and blood pressure are essential in regulating water and fluid balance, and they are vital to stimulating muscle and nerve cells. Sodium increases thirst stimulus and reduces physical fatigue and medical issues associated with homeostatic imbalances during endurance events. Sodium also decreases urine production and maintains electrolyte balance, increasing water retention (Veniamakis, Kaplanis, Voulgaris, & Nikolaidis, 2022).  It is important to follow medical guidelines since very high levels of sodium consumption can lead to an increase in kidney disease and is associated with the development of hypertension.  (Veniamakis, Kaplanis, Voulgaris, & Nikolaidis, 2022).

D3 sports nutritionists and coaches can help educate athletes on proper hydration and sodium usage during training and racing to maximize their performance including our Race Day Fueling Expert, Nick Suffredin.

Nick has a variety of articles written on D3 about how to calculate your sweat rate and more.  Nick is available for consultations to help you develop hydration strategies to improve your race performance.

Coach George Epley shares that “there’s nothing more rewarding than achieving that which once seemed impossible! Helping people get to that point is one of the things I love about coaching! My first commitment to an athlete is to optimize through customization. Each athlete has their own complex formula consisting of genetics, available training time and outside stress levels.” Coach George holds multiple coaching certifications including his Level II USA Triathlon Coaching Certificate.

Desmond, M., (2006) ACSM recommendations for endurance athletes, American Family Physician, 73(3)547. 
Hew-Butler, T., Loi, V., Pani, A., Rosner, H, M., (2017) Exercise associated hyponatremia: 2017 update, Frontiers in Medicine, 
Nieman, D., (2007) You asked for it, ACSM Health & Fitness Journal 11(3) 5-6. 
Veniamakis, E., Kaplanis, G., Voulgaris, P., Nikolaidis, T, P., (2022) Effects of sodium intake on heath and performance in endurance and ultra-endurance sports, International Journal Environmental Research in Public Health 19(6)365. 

Coach Geroge Epley has a passion for knowledge and believes it’s the key to maximizing your potential. He keeps abreast of the latest scientific studies, always trying to find more efficient and validated means of coaching his athletes. Knowledge in the form of communication is just as important. The more he knows about his athletes and the sooner he knows of changes in circumstances, lifestyle, or training, the greater resource he can be.

Coach George is a USA Triathlon Level II Certified Coach, USA Triathlon Youth & Junior Elite Certified, USA Cycling Elite Level, USA Cycling Cyclocross Certified, ACSM – Certified Personal Trainer, MBSC – Certified Functional Strength Coach, Training Peaks Coach and WKO4 Certified

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