The Fine Line Between Salt Restriction And Sweat
Sodium Intake Restriction Impact Sweat
Research and findings in this field were released before and after the Second World War. They paid close attention to low sodium consumption and the outcome it had on the composition of sweat instead of investigating how to sweat sodium concentration changed when the dietary sodium was greater than normal.
Generally, there were considerable drops in the concentration of sodium in sweat when sodium was removed from the diet, suggesting that the concept of ‘output being less when input is also reduced’ could be correct.
Although the results of those first studies are interesting, the issue with them is that it’s impossible to completely cut salt out of your food in everyday life – how often would you be able or willing to totally omit salt from your meals?
While it is not hard to refrain from salting dishes since most sodium comes from invisible sources, it is possibly more challenging than anticipated to drastically diminish sodium intake.
Hot baths were taken to induce sweating heavily while the individuals involved followed a stringent salt-free regimen, even going so far as to boil and drain foods to cut down their sodium content.
It is also important to remember that several of the primary examinations gauged salt content in sweat while not active.
Studies that tracked perspiration during physical activities typically showed the intensity of the exercise was lower than what athletes usually work out with while training or competing. The people involved were generally not physically active or had not been trained beforehand.
In a nutshell, the experiments were done excellently and with care, however, the results of these experiments do not reflect the lives of athletes today or the amount of sodium they typically lack while participating in physical activities.
At present, a lot of exploration is being led by Dr Alan McCubbin, a respected Sports Dietitian and researcher at Monash University in Australia.
In 2018, he and Ricardo Costa released a thorough examination to figure out the effect of dietary sodium consumption on perspiration sodium levels in answer to endurance exercise.
Out of the six investigations that met the guidelines, two revealed a noteworthy contrast in sodium sweat focus attributable to changes in dietary sodium consumption, two didn’t show any discrepant information, and the remaining two weren’t assessed numerically.
The difference in average sodium amount in sweat in these studies ranged from -5 mmol/L to +30 mmol/L.
The research discovered that on average, whole-body sweat sodium concentration varied by 4 mmol/L over six weeks when the subjects were given 3.4 g or 5.6 g of sodium each day.
A research project which only studied dietary sodium levels over two weeks found a difference of 12 mmol/L, even though the monitored sodium intake levels differed by a comparable amount (1.15g Na/day or 3.45g Na/day).
Many elements could be responsible for the divergence between the various studies.
For example, the research conducted had different salt consumption amounts from <196 to 9,177 mg/day, lengths of time for the experiment (3 up to 42 days), types of physical activity (such as pedalling on an exercise bike, running or walking on a treadmill), and processes used to collect sweat (like completely washing the entire body or using patch systems on specific areas).
Also, the people taking part consisted of some who had previous experience and some who had not, and some who had adapted and some who had not.
The differing outcomes of the research done using different intervention sessions could perhaps be attributed to how the sweat glands respond to changes in sodium levels and the associated transformation in an essential hormone called aldosterone.
Real-World Applications for Athletes
At the present, there is a large gap in the available literature about how much sodium endurance athletes consume in comparison to levels used in other dietary trials.
For example, one research conducted a high-sodium diet where participants ate more than 9 grams of sodium per day for four days, which is an extreme amount of sodium that is not typical for people in general, even for athletes with very high-level performance who may require more sodium in some settings.
In comparison to what many athletes would consume with a regular diet, studies on low sodium diets often have participants consume between 0.5 to 2.3g Na/day, which is much lower.
Tests that are not based on common sodium intake amounts will not reveal the shifts in sweat sodium levels when dietary sodium amounts are barely altered, as would occur with a person who is not restricted by a pre-determined diet.
Dr McCubbin and their colleagues attempted to address some of these obstacles in an article that came out in 2019. They ran a study where those taking part were instructed to consume their regular food.
When on their own, the average amount of sodium taken in by the subjects was 0.046 g/kg/day. McCubbin felt it was essential for all participants to receive an amount of dietary sodium by their body size.
The “high” trial stated the participants to consume 0.1 grams of the material per kilogram that they weighed per day, while the “low” trial required them to ingest 0.015 grams of the material for every kilogram of their body weight each day.
A diet with elevated sodium intake was selected to accurately represent an amount that could easily be consumed by endurance athletes on the day before exercising, as previously uncovered by the research team.
The research revealed that after tripling the salt intake in three days, the sweat sodium concentration rose by 10-12% (~6 mmol/L), which is a minor change that won’t have much of an impact on an athlete’s hydration and nutrition plan while exercising.
We had a discussion with Dr McCubbin on his paper and he brought up something essential.
He strongly believes it is essential to talk about dietary salt intake and sweat salt content in a realistic setting.
He declared that when it came to his paper, experts who work with athletes would be aware that a 6 mmol/L variation in sweat sodium concentration is not significant enough to affect how they set up their nutrition intake for a race.
Moderate Salt Consumption Is Likely Key
At the furthest boundaries of the discussion that is developing, people like Dr James DiNicolantonio, the author of The Salt Fix, have put forth their ideas in a scholarly article.
DiNicolantonio and a few of his colleagues are beginning to put forward the notion that other elements (e.g. elevated sugar consumption) potentially have a stronger impact on the building up of chronic high blood pressure than just sodium consumption.
Dr DiNicolantonio makes the assertion that, for the vast majority, an increase in salt consumption or lack of restriction based on personal preference probably will not have an effect on the blood pressure in a healthy person.
He strongly suggested that it might be even worse to add too little salt than it is to add too much, which caused a large amount of criticism in the press upon the release of his book since it is not a typical idea.
Though some of his beliefs may be a bit too strange for my taste, DiNicolantonio’s argument overall is convincing and backed up by lots of evidence that the current advice on limiting sodium intake may be misguided and could use some rebalancing.
He promotes the idea that the connection between the amount of sodium we consume and our health is not just linear but instead follows the shape of a ‘J’ much more closely.
The graphical representation of a “J” shape curve shows that, like any vital nutrient in the body, there are optimal lower and higher limits for a health condition.
Put differently, eating either too much or too little sodium can cause health problems, including influencing one’s blood pressure.
Research done in 2017 on 2600 Americans over 16 years appears to corroborate DiNicolantonio’s findings in that people who consumed less than 2500mg of sodium daily had a HIGHER blood pressure reading than those that ate more.
It appears to be an obvious reality that too little sodium in the diet has a negative effect, which is as critical as an excessive amount of sodium. Though further exploration is necessary to understand the precise processes that cause these results, the general understanding is both understandable and believable.
It is necessary to shift the discussion around sodium and blood pressure to focus on what is ideal, rather than aiming to propagate blanket upper limits on consumption, which had been the standard until now.
Sodium Intake for Athletes
If we recognize that having an inadequate sodium intake can be as problematic to the health and blood pressure as having an excessive sodium intake, then the discussion about how much salt athletes require becomes intriguing.
A person who does not exercise need not consume more than 2000 milligrams of sodium daily for their fundamental bodily requirements.
It is said that the regular Western diet contains around 3,400mg a day, being understandable how individuals can reach and pass this limit without having to consider it.
It is apparent why the general recommendation for reducing sodium intake may be reasonable, as most individuals probably consume more than their body requires.
But what about the athletes? The average litre of people’s sweat includes between 200-2000 mg of sodium and can easily reach up to 1.5-2 litres per hour for trained athletes. This means that those of us working out for hours on numerous days per week can experience greater sodium and liquid deficiencies in comparison to the rest of the population.
The number of losses that can occur can be much greater than the 2500mg or 3400mg of nutrition that is suggested or taken in with a typical diet.
Factoring in Sweat Rate and Sodium Loss
This is particularly pertinent for people who exude exceedingly large amounts of water and salt or anyone who partakes in competitive sports that necessitate long hours of practice or consecutive days of drills.
I, as an athlete, would not be getting enough of what I need nutritionally if I limited myself to the advised dosage of 2000mg/day, which would detrimentally affect my health and performance.
A fantastic research article examining the involvement of sodium in the nutrition of athletics accurately summarizes the subject.
It has become commonplace to acknowledge the increased hydration needs of athletes who perspire a lot, however, it has largely gone unrecognized that they likely need much more salt too – this could be due to the common misconception that salt is ‘unhealthy’.
An intriguing examination of a German athlete demonstrated the ill effects of excessive training, which included symptoms of overtraining and elevated blood pressure when taking part in regular endurance-based activities.
At the moment, she was adhering to a diet low in sodium that she thought was “healthy”. She didn’t have to reduce the amount of training and exercise she was doing, which would usually be necessary to avoid the over-training syndrome, all she had to do was increase her dietary intake of sodium.
A large number of athletes we have heard from over the years have tried to abide by the guidelines for optimal nutrition by eating low sodium yet working out heavily, leading to the loss of considerable amounts of sodium through perspiration.
The American Heart Association proposed a goal of 1500mg of sodium each day as a generic recommendation, but it also pointed out on its website that too little sodium is not actually a public health issue in the United States. The recommendation to cut back to a maximum of 1,500mg of sodium a day doesn’t hold for competitive athletes and individuals who are regularly exposed to extreme weather conditions in jobs like firefighters, or individuals whose healthcare provider has advised them otherwise. You should listen to the counsel of a professional in healthcare if you have any physical ailments or dietary needs or limitations.
Best Practices Might Be Net-Zero
Athletes or anyone who perspires heavily during the day should make an effort to consume the same amount of sodium they lose through sweat as a minimum.
Ideally, sodium consumption should be beneficial for everyone involved with no one at a disadvantage.
The amount taken in should counterbalance what is used up, leading to an overall sodium balance that is not affected, so in theory, there would be no change in blood pressure or other body measurements.
According to Dr DiNicolantonio, having a bit more salt than your body needs should be acceptable, as long as one’s kidneys are in proper condition, as the body can handle an abundance of its intake and prevent a lack in the future.
In conclusion, it is vital to note that I am not a medical specialist and that nothing written in this article should be treated as authoritative advice on how to act if you are a sportsperson anxious about the effect of sodium intake on blood pressure.
It seems that certain individuals may react differently to consuming salt than others, so if you have been diagnosed with high blood pressure or a related issue, it is wise to consult with your physician before altering your dietary habits.
The effects sodium and fluid have on blood pressure medications have yet to be discussed, but they involve intricate connections.
The point of this article is to provide insight into an intricate and debatable subject regarding health and performance and to potentially cause readers to think critically about it.