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We’ve been told for years that salt is bad. Too much salt can cause high blood pressure (hypertension), so we all need to restrict it, right?

Wrong. In fact, a study from 2011 actually found that salt-restricted diets made matters worse for people with heart disease.

Why You Need Sodium in Your Diet

Salt gets a pretty bad reputation from conventional nutrition, but it’s something that all athletes need in their diets. When we exercise, our heart rate and core body temperature increases, and our body responds by secreting fluid (or sweat) through the pores of our skin.

When sweat evaporates off of the skin, it provides a cooling effect that helps the body avoid overheating. The majority of what we lose in sweat are fluids (water) and sodium, so replacing these nutrients is key to maintaining proper hydration.

Sodium needs will vary from athlete to athlete based on a few factors:

  • Acclimation to weather
  • Duration of exercise
  • Saltiness of sweat

Weather Acclimation

Hot climates can drastically reduce your climbing performance if you aren’t used to the heat. Sodium needs tend to increase significantly as you acclimate to warmer weather, but once your body is accustomed to the heat, it will become more efficient at retaining and utilizing sodium – which means you’ll be able to perform better with less sodium.

On the first day of exercise in a hot, dry environment, the volume of your blood plasma increases by about 13%. This means that unless you increase your sodium intake, you will most likely be dehydrated. The same thing can happen on the first day of cool weather after months of training in the heat, so be sure to increase your sodium intake when the seasons change. For me, that won’t be happening until about Halloween.

Exercise Duration

This variable is pretty straight-forward. If you spend 4 hours hiking to an area where you climb for 5 to 6 hours, then a) I do not envy your approach and b) you need more sodium than someone like me who might hike 5 minutes down into a canyon to climb for 3-4 hours, assuming that we have the same weather.

Saltiness of sweat

This variable is completely dependent on the person. Some of us are just saltier by nature, and thus lose more sodium than others after doing the same amount of exercise in the same climate. If you’re like me, then you might notice a dried white line on your clothing after working out. This is an indication that you’re a salty sweater, and that you may need to increase your sodium intake to keep up with your sodium losses.

Signs You May Need More Sodium

The most accurate way to calculate your sodium needs is to get lab testing done, but this may not be available to everyone. So it may be more practical to estimate your needs through trial and error. If you frequently experience any of these symptoms at the crag, then you could likely benefit from more sodium in your diet or in your sports drinks.

  • Headache
  • Fatigue
  • Nausea/vomiting
  • Irritability
  • Muscle cramping
  • Muscles weakness
  • Confusion/grogginess

Risk Factors for Hyponatremia (Not Enough Sodium)

You can also estimate your sodium needs by understanding what increases your risk for hyponatremia.
  • Being a woman – yay!
  • Being over the age of 50
  • Taking thiazide diuretics, some antidepressants, Ecstacy, or NSAIDS (aspirin, ibuprofen, naproxen)
  • Drinking alcohol (aka having fun)
  • Drinking too much plain water (without electrolytes)
  • Being a newer climber
  • Having Addison’s disease, kidney disease or heart failure


Hopefully you now understand the importance of sodium in your diet. Most Americans get plenty of sodium in their diets from deli meats, canned foods, cheeses, and nuts, but there’s a chance that you could need even more salt in your diet.

If you live somewhere with a hot climate, frequently climb outdoors, and experience any of the symptoms of hyponatremia, be sure to pack a salty snack for the crag or a sports drink with plenty of sodium. Climbing in the heat makes me cranky, so I’m fairly certain that I’m not getting enough… Are you getting enough sodium? Leave a comment below 🙂


  • Mike says:

    Our ancestors apparently ran down Antelopes on he African savannah and they didn’t have added salt in their I am a little confused. I always thought the reason modern atheletes sweat salt is because it is the “cheapest” way for the body to get rid of something it doesn’t want.

  • Aicacia says:

    Hi Mike! Great question. Salt has actually been used for a long time. It was documented in Chinese pharmacology dated back to 2700 BC and used habitually by the Egyptians dating back to 1450 BC. It’s of course impossible to know how much salt our ancestors consumed and how much sweat they produced, but most likely they still lost sodium in their sweat. Your body uses sodium and potassium to create a voltage difference, similar to a battery, to trigger muscle contractions. So your body definitely wants sodium, but it gets rid of it once it can no longer be used.

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