Sodium for Strength Athletes: What the Evidence Says
Commercial salt supplementation options.
Sodium supplementation is growing in popularity among strength athletes. Traditionally a focus for endurance or team sports, some popular nutrition coaches are now championing high sodium consumption as vital for optimal health and performance in strength sports. Others still have reservations about the risks of intake greater than the recommended daily amount (RDA) set forth by health associations. Unfortunately for strength athletes, including strongmen/women, the majority of research on salt and electrolyte supplementation has been conducted on endurance athletes, but we can make some inferences about its impact on things like sweat rate, rate of perceived exertion, and temperature regulation that might suggest a benefit.
Sodium Basics
We usually eat sodium in the form of table salt or sodium chloride, which is actually an ionic compound containing one atom of sodium and one atom of chloride. When in solution these atoms separate and sodium becomes an electrolyte necessary for human life via regulation of fluid balance, blood volume, blood pressure, body pH, and more. The American Heart Association recommends consuming no more than 2,300mg of sodium, or 1 teaspoon of salt per day for adults to reduce the risk of high blood pressure or other negative cardiac outcomes (1). However, the average American consumes about 3,400mg of salt per day, and people in other countries average up to 5,000mg (2,3). Findings suggest intake comes primarily from processed foods and/or food additives rather than excessive use of the salt shaker. It is worth noting that larger athletes may simply take in more food than smaller athletes and are likely to exceed the average intake considerably.
For athletes, the recommendation for sodium can be higher in certain situations. Sodium is the main electrolyte lost in sweat during exercise, and sweat rates can vary from 0.3 to 2.4 L/hr depending on intensity, duration, conditioning level, heat acclimatization, altitude, and other environmental aspects, like humidity (4). The amount of sodium in one’s sweat also varies depending on factors including genetic predisposition and heat acclimation but is around 1,000mg per liter of sweat (5). A 2-hour workout for an average “sweater” might lead to a loss of around 2,000mg of sodium.
Risk factors for hyponatremia, or low salt levels in the blood (6).
With the potential for significant losses, it seems like supplementation prior to or during exercise would be optimal. However, the body tightly regulates blood sodium levels even when you have not eaten salt in a while. In rare cases when blood levels drop, it creates a serious and sometimes deadly condition called hyponatremia. This condition is more common in endurance athletes exercising >4 hours in hot environments, smaller individuals, and those who drink large amounts of fluids before and during the athletic event (6). Interestingly, it is believed that this condition in healthy individuals is caused by dilution, or overconsumption of water vs. inadequate salt intake, and it is unclear whether supplementing with sodium and fluids during the extended events will prevent the condition from occurring.
Salt Supplementation
Though clinical hyponatremia is not typically seen in strength athletes, some theorize that even mild sodium loss may inhibit strength by altering the body’s nerve conduction abilities. A 2016 study investigated the impact of hyponatremia on nerve conduction and muscle strength and found no difference among people with mild to moderate hyponatremia, and no improvement when levels were corrected via sodium intake (7). A study of athletes participating in a Half-Ironman competition found that a salt supplement prior to competition helped retain body weight post-race, but had no effect on whole-body strength or jumping power (8). It appears that even if you become low in sodium acutely, it does not seem to affect strength or power.
Subjective RPE during endurance exercise with and without salt.
If strength is unlikely to change with salt supplementation, it is possible that insufficient sodium intake could impact performance in other ways. Yet, a 2015 study put subjects through a 2-hour aerobic challenge before immediately assessing their performance in a high-intensity time to exhaustion test both with and without a 1,800mg sodium supplement (9). The supplementation failed to improve performance, affect their Rate of Perceived Exertion (RPE), or alter their sweat rate or other markers of temperature regulation. A recent review paper on the effects of sodium on endurance performance concluded that there was insufficient evidence to support sodium supplementation to prevent or treat exercise-induced cramping, and though sodium-rich beverages might aid in faster re-hydration than water alone, performance benefits are unclear (10). Overall, it seems that some additional salt might be helpful for maintaining weight and hydration status in certain situations, but the amount that is needed is probably overstated by proponents, and a strong link to performance has not yet been made.
For long workouts in the sun, some additional sodium is advised.
Despite the lack of evidence supporting a substantial benefit to sodium supplementation, major sports nutrition organizations recommend adding a small amount in certain situations to be conservative. The International Society of Sports Nutrition recommends adding 300-600mg of sodium per hour for individuals who are participating in extended exercise bouts (11). The Academy of Nutrition and Dietetics suggests similar supplementation for exercise lasting >2-hours, and for those who are prone to heavy sweating (12). This may not be helpful specifically for performance, but can fight off heat and dehydration-associated cramping in some people, though the current consensus is that the majority of cramps are not electrolyte-related. It has to be noted that 300mg of sodium is less than is in most sodium supplements, and can easily be taken in via food, for example with a single serving of pretzels or 1/8 tsp of table salt in your water bottle.
Conclusions
Ultimately strength athletes like strongmen/women, powerlifters, and weightlifters probably don’t need to be supplementing with high amounts of sodium before every workout. Given the potential negative effects of excessive salt intake on health outcomes, it is a good idea to avoid this practice unless recommended by a healthcare professional or in the specific circumstances outlined in this article. If you believe you may require supplementation, simply add 300-600mg of sodium per hour for long, intense and/or hot sessions via a snack, sports drink, or pinch of salt. This should be more than enough to aid in water retention, reduce the risk of clinical hyponatremia, and possibly make your beverage more tasty and thirst-quenching.
Sodium Recommendations
2,300mg/day normally
Consider adding 300-600mg per hour of exercise if:
You are exercising for >90 mins
You are a heavy sweater
You are exercising in hot/humid conditions
You are prone to muscle cramping
You will be sweating for long periods of time as in an outdoor competition setting
You make all your own food, are on a low calorie diet, and do not add salt when cooking
*If you have high blood pressure or are at risk for heart disease, speak to your healthcare provider before adding sodium to your workout regimen
References
Shaking the Salt Habit to Lower High Blood Pressure. www.heart.org. Last Reviewed: Oct 31, 2016.
Wallace, T.C., Cowan, A.E., Bailey, R.L. (2019). Current Sodium Intakes in the United States and the Modeled Effects of Glutamate Incorporation into Select Savory Products. Nutrients. Nov; 11(11): 2691.
Powles, J. Et al. (2013). Global, regional and national sodium intakes in 1990 and 2010: a systematic analysis of 24 h urinary sodium excretion and dietary surveys worldwide. BMJ Open. Dec 23;3.
Thomas, D.T., Erdman, K.A., Burke, L.M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet. Mar;116(3):501-528.
Turner, M.J., Avolio, A.P. (2016). Does Replacing Sodium Excreted in Sweat Attenuate the Health Benefits of Physical Activity? Int J Sport Nutr Exerc Metab. Aug;26(4):377-89.
Rosner, M.H., Kirven, J. (2016). Exercise-Associated Hyponatremia. Clin J Am Soc Nephrol 2: 151–161.
Vandergheynst, F. et al. (2016). Impact of Hyponatremia on Nerve Conduction and Muscle Strength. Eur J Clin Invest. Apr;46(4):328-33.
Del Coso, J et al. (2015). Effects of Oral Salt Supplementation on Physical Performance During a Half-Ironman: A Randomized Controlled Trial. Scan Jour of Med and Sci in Sports. 26:2; 156-164.
Earhart, E.L., et al. (2015). Effects of Oral Sodium Supplementation on Indices of Thermoregulation in Trained, Endurance Athletes. J Sports Sci Med. Mar;14(1): 172–178.
Veniamakis, E. Et al. (2022). Effects of Sodium Intake on Health and Performance in Endurance and Ultra-Endurance Sports. Int J Environ Res Public Health. Mar; 19(6): 3651.
Kerksick, C.M. et al. (2017). International society of sports nutrition position stand: nutrient timing. JISSN, 14:33.
Thomas, D.T., Erdman, K.A., Burke, L.M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet. Mar;116(3):501-528.
