It’s part of your natural physiology to lose sodium through sweating. But how much sodium do you lose in sweat? You tend to lose anywhere from 200mg up to 2,300mg of sodium per liter of sweat. However this range reflects the two extremes on the spectrum, where if you are only losing 200mg per liter, you are perfectly acclimated to living, working, and exercising in hot weather. But if you’re dumping out an incredible 2,300mg of sodium per liter of sweat, this generally means you have a high sodium diet.
What is the normal range of sodium concentration in sweat?
Depending on which study you look at, the normal range of sodium concentration in sweat is anywhere from 230mg to 1,610mg per liter, with a median of 830mg per liter. According to Medscape, this concentration is not dependent on your sex or age. I’ll list a series of studies below, with their conclusions regarding normal sodium amounts in sweat:
| “Does Replacing Sodium Excreted in Sweat Attenuate the Health Benefits of Physical Activity?” in the International Journal of Sport Nutrition and Exercise Metabolism | 40-60mmol/L (0.92-1.38g/L) |
| Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability | 10 to 70mmol/L (0.23 to 1.61g/L), with the median being 36mmol/L, or 0.83g/L of whole body sweat |
| Relationships between micronutrient losses in sweat and blood pressure among heat-exposed steelworkers” in the NIOSH journal, Industrial Health | 1.08g/L (mean) |
| Gatorade Sports Drink | 0.46g/L |
Do you need to replace sodium lost through sweat?
If you’re exercising, or in the heat, more than 1 hour, then you should consider replacing the sodium you lost through sweating. If you’re a typical sweater, with a median loss of sodium, then after 1 hour you’ve lost a little less than 1 gram of sodium. That could be anywhere from 43 to 66% of you daily intake of sodium, if your diet allows for 1,500 to 2,300mg of sodium per day.
How do you replenish salt after sweating?
If you’re sweating from performing some type of exertional activity or exercise that lasts over an hour, then you should be replacing some of that sodium loss via a sports drink that also has liquid carbs to offset your glycogen store loss. But that sports drink will only partially replete your sodium. And generally you have to seek out oral rehydration solutions to replete chloride, another essential electrolyte in your body that is lost through sweat.
Once your activity is over, then you should be focusing on repleting even more carbs, protein and salt, all together, for the purposes of muscle recovery. Below I’ve listed a set of salty protein snacks, with a few backpacking meals listed as well, that do have some carbohydrates needed for post hike recovery.
Related: Protein and carbohydrate timing with regard to high exertion hiking for proper recovery
Backpacking meals from Mountain House usually have high amounts of sodium, not only to get those multi-decade expiration dates, but to help you gain back sodium lost in your sweat from backpacking all day.
Salty foods with protein to replenish sodium lost to sweating
| Salty foods to replenish sodium after sweating | Sodium per serving |
|---|---|
| The Only Bean Crunchy Dry Roasted Edamame Snacks (Sea Salt), Keto Snack Food, High Protein (11g) Healthy Snacks, Asian Japanese Snack Gluten Free Lunch Vegan Food 100 Calorie Snack Pack, 0.9oz | 150mg |
| Planters Salted Peanuts Single Serve, 2.5oz Bag (19g protein) | 240mg |
| Quest Tortilla Style Protein Chips Variety Pack, Chili Lime, Nacho Cheese, Loaded Taco (19g protein) | 340mg |
| Good-To-Go Mushroom Risotto (freeze dried backpacking meal) (13g protein). 1 bag = 1x serving | 420mg |
| Jack Link’s Beef Jerky, Original – Great Everyday Snack, (10g of protein) and 80 Calories, Made with 100% Beef; x1 serving | 460mg |
| Mountain House Beef Stew (freeze dried backpacking meal) (10g of protein). 1 bag = 2x servings | 790mg |
How do you feel if your sodium is low?
It may be difficult to tell if your sodium is too low, because if it is only slightly low, you may have no symptoms. Further, once your levels fall below a certain point, your symptoms are not specific enough to conclude they are definitely from low sodium. The early symptoms of low sodium, i.e. hyponatremia, may also be similar in nature to those from dehydration. You might have a headache, experience tiredness, and also nausea.
However, if your sodium falls too fast – acute hyponatremia – this can trigger neurological and muscle related symptoms, and be life threatening. You could experience headache, nausea and vomiting, confusion, fatigue, drowsiness, irritability, restlessness, muscle weakness, spasms, cramping, and finally seizures, coma and death. Generally if your sodium levels go up or down by more than 10 or 12mEq/L of plasma, within 24 hours, that is considered too fast of a change, and can precipitated neurological symptoms.
One reason related to hiking, backpacking and thru-hiking, that your sodium could fall very fast is that you are drinking too much water, but not taking in enough sodium on the trail. That excess water can show up in your brain, causing cerebral edema, which can put enough pressure on your brain to cause herniation, and possibly death from such.
It’s important to note that the only sure way to know if your sodium is low is to have your blood drawn, and read by a medical laboratory.
Further Reading
Thanks for checking out my article on how much sodium you lose when you sweat. Check out my hiking nutrition library of articles, where I have other electrolyte and fluid related writings, calorie and sweat rate calculators, etc.