Ditch Your Sea Salt Water For This Post-Workout Tonic
Don’t Fall For The Sea Salt Craze! Science Explains Everything
The latest fad is to drink sea salt water after a workout. Have you ever seen any research to back this up? We’ve gathered the key scientific findings relating to sea salt and exercise in this expert article. If you read it, not only will you become an expert in debunking this fad with your friends, we’ll also share with you a delicious post-workout tonic to replace your sea salt water!
What’s the deal with adding sea salt to water after exercise? Why are people doing it?
The sea salt water craze originates from the idea that when you sweat, you lose electrolytes that aren’t found in unsalted water.
You’ve probably heard of the term “electrolytes” before. It’s popular in advertising. But, have you ever stopped to think about what electrolytes actually are?
Electrolytes are constituents of living cells that have a positive (+) or negative (-) charge. Salt is primarily made up of two electrolytes: sodium (Na+) and chloride (Cl-).
The positive charge of sodium and the negative charge of chloride make these electrolytes a great pair. When sodium and chloride come together, they form a solid, crystal substance called sodium chloride (NaCl). This is what we call “salt”.
It’s true that when you sweat during exercise, you don’t lose pure water; you lose electrolytes as well (Shirreffs and Sawka, 2011). Scientists have conducted “sweat tests” to measure the amount of sweat that humans lose during exercise, and how much of that sweat is sodium (Baker, 2017).
Let’s assume for a minute that you’re a scientist and you want to find out how much sodium you lose in sweat so that you can replace it with sea salt water. What would your “sweat tests” reveal?
First of all, it’s extremely difficult to measure how much you sweat. You can measure changes in your body mass by comparing your pre-exercise and post-exercise weight. However, there’ll always be some sweat trapped in your clothing (Baker, 2017). And, how much you sweat isn’t the only factor that will influence your body weight (Baker, 2017).
If you really want to replace the electrolytes that you lose during exercise, you need to consider all of the following:
- how old you are,
- whether you’re male or female,
- how intensively you worked out,
- the conditions of your environment,
- how well adjusted you were to your surrounding temperature,
- your aerobic capacity (how quick your oxygen uptake is),
- your body size and composition (e.g. how much of you is fat vs muscle),
- what you ate beforehand and/or whilst exercising,
- what you were wearing,
- how hydrated you were at the time of collection, and
- how much you peed.
Secondly, it’s not just how much you sweat that matters; it’s the amount of sodium in your sweat that counts. Depending on whether you measure sweat loss from your entire body or from an isolated body part, you’ll get different results (Baker, 2017). You’ll also have different sodium concentrations in your sweat at different times of day (Baker, 2017). And, if you use products on your skin, such as face wash, this could influence the amount of sodium found during “sweat testing” (Baker, 2017).
I don’t know about you. But, if scientists who are experts in sweat collection can’t accurately work out how much sodium you lose during exercise, I don’t think you can either.
This brings me to my first point. If you don’t know how many electrolytes you’re losing during exercise, how do you know if you would benefit from drinking sea salt water after a workout? Point made.
Now, let’s consider why humans need electrolytes.
Sodium chloride is extremely helpful in regulating the amount of fluid in your body (Feraille and Dizin, 2016). Your kidneys rely on sodium chloride to do their job properly:
- removing unwanted substances from your blood,
- regulating your blood pressure, and
- making sure there’s enough fluid in and around your tissues.
How? Pumps in your kidneys move electrolytes, including sodium and chloride, in and out of your blood. This electrical activity encourages the movement of water, other electrolytes, and metabolic substances in or out of your blood until you have the perfect balance of fluids in your body (Wang, Weinbaum, and Weinstein, 2017).
Fluid balance is an example of homeostasis. Homeostasis is your body’s ability to keep everything in its internal environment in a state of balance.
Sodium is also vital for your nerves to communicate with each another and other parts of your body. For instance, to move part of your body, your muscles must contract. For this contraction to happen, your nerve cells have to send chemical messages from your nerve cells to your muscle cells.
How is this relevant? The electrical stimulation that sodium provides allows your nerve cells to transmit these chemical messages to your muscle cells (Adam and De Luca, 2005). Therefore, sodium chloride (a.k.a. salt) is essential for exercise to take place. This is one of the reasons why sea salt enthusiasts are so… well, enthusiastic about sea salt!
If salt plays such a crucial role in human health, why are we so against drinking sea salt water after exercise?
It’s true that you can die from drinking water without electrolytes in it (Wen, 2014). When there’s too much fluid in your body for your kidneys’ filtration system to keep up with, your sodium concentrations can drop to critical levels (Hew-Butler et al., 2017).
But, dangerously low sodium caused by overhydration is extremely rare. This life-or-death physiological state only tends to occur in prolonged endurance events, like triathlons and marathons (Wen, 2014). Even marathon runners, who have particularly large amounts of sodium in their sweat, very rarely experience a significant depletion in electrolytes (Lara et al., 2017).
Also, research shows that humans can easily tolerate mild dehydration (losing up to 3% body weight in water) with no real health implications (Hew-Butler et al., 2017).
To put this into perspective, American Football players are at a higher risk of heat stroke than other athletes due to their greater body mass, higher body fat percentage, lower aerobic capacity, and the fact that they stand around a lot (Davis et al., 2016). However, players typically lose less than 2% of their body weight in water during a game, which is insignificant (Davis et al., 2016).
Ultimately, homeostasis is your body’s top priority. It needs to keep all of your internal systems in balance in order for you to survive (Diringer, 2017). It’s for this reason that consuming salt during exercise doesn’t actually prevent overhydration (Hoffman and Myers, 2015) or enhance athletic performance at all (Cosgrove and Black, 2013). Irrespective of what you eat or drink, your kidneys will work overtime while you exercise to make sure that your electrolytes don’t get to critical levels.
What about after exercise? The same is true after a workout. Your kidneys don’t suddenly stop working just because you’ve been lifting weights. Unless you have kidney failure or are acutely unwell, your electrolytes will easily get back to their normal levels after exercise (Diringer, 2017). The fact of the matter is, drinking “electrolyzed water” won’t rehydrate you any faster than normal water (Weidman et al., 2016).
The only exception to this rule is if you’re an elite athlete and need to give your kidneys a helping hand because you’re going to train or compete again within the next couple of hours (Jeukendrup, Jentjens, and Moseley, 2005). If this is you, ditch your sea salt water and check out this delicious, electrolyte-rich, post-workout tonic!
So, what’s the bottom line when it comes to sea salt and exercise?
If you’re an average Joe, working out for up to 2 hours per day, eating and drinking regularly, and not suffering from subpar kidney function or an acute illness, ditch that sea salt water (and any other “electrolyte-replacing” drinks you have lurking around) and never look back! (Shirreffs and Sawka, 2011)
Research shows that you’re better off drinking when you’re thirsty and getting on with your day (Hew-Butler et al., 2017). Globally, sodium intakes are well in excess of daily requirements (McLaren et al., 2016). If you live in Canada, 75% of your salt intake is hidden in your food (Brown et al., 2009). So, you’ll easily replace your electrolytes from sweat when you next have a meal (Maughan, Leiper, and Shirreffs, 1996).
Written by Sophie Ash, BSc (Hons), DipION, NNCP — Research Analyst, Nutritional Therapist, and Gastrointestinal Specialist (www.onyourplate.ca).
