Do Athletes Need More Daily Sodium?

[Adammc192]

I know the typical answer to this is yes.

However, I can’t seem to find any data to support the extra need for sodium other than the reasoning that athletes sweat more and thus lose more Na+.

This is with the exception of staving off hyponatremia. There doesn’t seem to be any studies looking at how much/any sodium athletes should consume during exercise but Dr. Alan McCubbin released this modelling paper this year which gives some really good insights: Modelling sodium requirements of athletes across a variety of exercise scenarios - Identifying when to test and target, or season to taste - PubMed

That moreso relates to Exercise associated hyponatremia as I believe that can be more common due to changes in anti-diuretic hormone while exercising.

So it’s pretty clear that some people (mainly over drinkers or ultra-distance athletes) should consider sodium replacement during exercise to avoid hyponatremia.

I also know that in general athletes can sweat on average 1-1.5L/h with a 40mmol concentration of sodium (on average).

I am only aware of one paper looking at changes in sodium intake it’s reflection of sodium sweat concentrations, what it found was a 50% approximate reduction in sodium lead to a 12% decrease in sweat concentrations and the inverse was also true. Impact of 3-day high and low dietary sodium intake on sodium status in response to exertional-heat stress: a double-blind randomized control trial - PubMed

There may be more papers and that was only a 3 day trial.

The reason I ask is we always hear athletes should eat more because they sweat out a lot of salt, but I wonder is that just a reflection of habitual intake since blood sodium concentrations will always try to remain between 135-145?

Personally, I have hypertension that won’t respond to medication (getting further tests) and my cardiologist has recommended to try get my sodium as low as possible and potassium as high as possible which makes sense.

I consume <1500mg/day but I play basketball competitively multiple times per week as well as run mid distance, sometimes the same day as lifting. If I was even an average sweater and had average sweat sodium concentrations one might assume that I am underconsuming salt, or losing more on a daily basis than I am intaking.

However, we’ve seen from the INTERSALT paper that some tribes consumed as little as 200mg/day, so there must be some adaptations.

In my N=1 experience, I don’t think I have noticed any downsides but is is possible that there potentially could, particularly around non sympomtaic hyponatremia?

My experience and digging has really led me to think that maybe athletes don’t need as much sodium as we say, and could it potentially be putting them at greater relative risk for CVD?

[Jordan_Feigenbaum]

Exercise-associated hyponatremia does not tend to be severe or cause symptoms and does not appear to be altered with sodium replenishment during or after exercise. Yes, sweat rates, water losses, and composition thereof can be used to determine replenishment needs for short-term (< 4 hours or so) applications, but this doesn’t really matter outside of that.

The averages you cited are not really practically applicable because the range and distributions are so wide. I would not use them for prescriptive purposes.

Sodium intake tends to be higher in individuals who lose a lot of sodium, and specific management is not typically needed. It is extremely unlikely that most people under-consume sodium in a way that decreases health or performance. The body tends to regulate sodium levels very, very well, such that micromanagement isn’t needed. Consuming too much sodium is problematic, particularly from foods high in sodium content. While sodium replacement via supplementation doesn’t appear to have good evidence for benefit in athletes outside of MAYBE short term recovery for multi-competition days, I do think recreational athletes using sodium supplements MAY be at higher risk of ASCVD by using them, particularly if they have other risk factors that would be exacerbated by a higher level of sodium intake.

In general, individuals who need more Calories will consume more sodium from food. Athletes tend to fall into this category, but I do not think there’s ample evidence that they need to supplement sodium.