In my last article, I talked about the importance of water and how much to drink.   But to be truly “hydrated” means to have a balance of water and chemicals called electrolytes.

Electrolytes include: sodium and chloride (aka salt), potassium, calcium, and magnesium.  These compounds help control muscle contractions, nerve impulses, blood pH, and water transport in and out of cells (kinda important, eh?).    The body works hard to keep it’s electrolytes in harmony with each other- each one requires an optimal concentration.  Training, illness, and medications can disrupt this balance. 

Electrolyte Balance

Dehydration = too much salt (sodium) and not enough water

When we exercise, we sweat, losing body fluid containing both salt and water.   We lose more water than salt, causing an electrolyte imbalance.   This change in salt concentration triggers our brain to send a signal that we are thirsty.  But as I’ve mentioned, there’s a “lag” in this system.  We usually don’t notice we are thirsty until we’ve lost around 1-2% of our body fluid.   

“If you’re thirsty, you’re already dehydrated?”  There’s truth to that.    

At this point, performance is probably not at peak state.  If fluid loss continues, things get more serious.  Other signs of dehydration are:

• Headache
• Fatigue 
• Flushing of the skin
• Low blood pressure
• Dizziness 
• Nausea, diarrhea, vomiting
• Heat sensations or chills
• Gastrointestinal cramping
• Rapid heart rate

Even worse:  heat cramps, fainting (heat syncope), heat exhaustion, heat stroke, coma, and death.  

Signs of heat exhaustion:

• Excessive fatigue
• Headache, dizziness, confusion
• Fainting 

Signs of heat stroke:

• Collapse
• Cognitive changes (aggressiveness, irritability, confusion, seizures, altered consciousness)
• Core temperature over 105 degrees

*These are emergency situations – if an athlete shows signs of heat illness, move them to a cool/shaded area. Cool with fans or ice towels.   Monitor the athlete closely, rehydrate them, and elevate legs above the heart. Call EMS if their condition worsens.   For more information, see the National Athletic Trainer’s Position Statement on Exertional Heat Illness. 

 

Over-hydration (hyponatremia):  too much water; not enough salt (sodium) 

Too much water will dilute the concentration of the electrolytes in the body –  not a good thing either.   So drinking too much can be just as dangerous.  Even life-threatening.   This is called hyponatremia (a fancy term for “low sodium in the body”). 

Athletes are at risk for hyponatremia because they might be overly motivated to stay hydrated and drink too much water.  Or, they fail to balance their water intake with a sports drink that has electrolytes like sodium and potassium.   

Symptoms of hyponatremia are scarily similar to dehydration. 

• Nausea, vomiting, other GI issues
• Headache
• Swollen feet or hands
• Confusion
• Altered mental status (acting “out of sorts”)

This can cause the athlete to be given more water, making the issue worse.   

 Tips for avoiding hyponatremia:

• Hydrating is important!   But don’t drink too much at once.  The body can only absorb 1.5L (6 cups) of liquid per hour. 
• Plain water is ok for most people when exercise or training sessions are not intense or shorter than 1 hour
• If you need to replace a lot of fluid (ex: intense exercise, hot or dry weather weather, losing fluids from vomiting or diarrhea) use an electrolyte solution

 

 

Keeping the balance

Athletes who need more than just water can drink a solution that contains both electrolytes and carbohydrates. 

Carbs get a bad rap nowadays, but they are important for intense or prolonged exercise.   Here’s the good things they do:

• Help the body absorb the liquids you are trying to replenish
• Improve recovery from training 
• Boost immunity
• Help the body make glycogen and glucose to keep exercising or store for your next training session

A sports drink needs to be less than a 10% carbohydrate concentration though-  more than that will cause stomach issues.     Drinks that are diluted will be absorbed quicker by the body too (more concentrated = more time spent digesting the drink = more time for it to be effective).  

You can also add a small amount of of protein to help with muscle recovery.   For more info see this article.  

So what should I drink and when should I drink it?

Intensity	Duration	Before	During	After	At meals	Additional
Moderate (light jog, yoga)	Under 2 hrs		2-4 cups water	2-4 cups water	1-2 cups water	For extra recovery (optional): add 10-15g protein to post-workout drink, like Thorne Research.
High (CrossFit, high intensity spinning/rowing/cardio)	Under 1 hr		2-4 cups water	2-4 cups water	1-2 cups water	For extra recovery (optional): add 10-15g protein to post-workout drink, like Thorne Research.
Moderate (distance running, day-long sports tournaments)	Over 2 hrs	1-2 cups water (30-60 min prior)	30-45g carb + electrolytes (sodium, potassium) in 600mL water every hour (Skratch labs or Nuun make good hydration mixes)  *consider adding 15g protein every hour of exercise as well	30-45g carb + electrolytes in 600mL water *add 15 g protein if less than 4 hour recovery before second bout of exercise or with long endurance events (like Thorne Research)	1-2 cups water	Add more/less water throughout the day based on your individual needs.
High (day-long sports tournaments,  triathlon, endurance competitions)	Over 1 hr	1-2 cups water (30-60 min prior)	30-45g carb + electrolytes (sodium, potassium) in 600mL water every hour. (Skratch labs or Nuun make good hydration mixes)  *consider adding 15g protein every hour of exercise as well	30-45g carb + electrolytes in 600mL water  *add 15 g protein if less than 4 hour recovery before second bout of exercise or with long endurance events (like Thorne Research)	1-2 cups water	Add more/less water throughout the day based on your individual needs.

*If you use a sports drink, DON’T wait until competition day to try it.  Use training sessions to try different brands and see what works (or what doesn’t!)

 

BOTTOM LINE:

• Water is fine for most people.   Make sure you’re drinking enough. 
• Use a sports drink when training in hot/dry climates or at high altitude.  Or, with:
  • Multiple training sessions/events in a day
  • Endurance training
  • High intensity training

 

CLE Sports PT understands that hydration needs vary for each person, activity, and training cycle.  Schedule a nutrition consult to determine your own needs and get a realistic plan to hydrate properly on YOUR schedule.  Or try a 15 minute free consult to get your hydration questions answered.  

 

 

REFERENCES:

1. Berardi, John et al. The Essentials of Sport and Exercise Nutrition. Precision Nutrition, Inc, 2017.
2. Casa DJ, DeMartini JK, Bergeron MF, et al. National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses. Journal of Athletic Training. 2015;50(9):986-1000. doi:10.4085/1062-6050-50.9.07.
3. American Dietetic Association; Dietitians of Canada; American College of Sports Medicine, Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009 Mar;41(3):709-31. doi: 10.1249/MSS.0b013e31890eb86.
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6. McDermott BP1, Anderson SA2, Armstrong LE3, Casa DJ3, Cheuvront SN4, Cooper L5, Kenney WL6, O’Connor FG7, Roberts WO8. National Athletic Trainers’ Association Position Statement: Fluid Replacement for the Physically Active.  J Athl Train. 2017 Sep;52(9):877-895. doi: 10.4085/1062-6050-52.9.02.
7. Rustad PI1, Sailer M2, Cumming KT1, Jeppesen PB3, Kolnes KJ1, Sollie O1, Franch J4, Ivy JL5, Daniel H2, Jensen J1,6.  Intake of Protein Plus Carbohydrate during the First Two Hours after Exhaustive Cycling Improves Performance the following Day. PLoS One. 2016 Apr 14;11(4):e0153229. doi: 10.1371/journal.pone.0153229. eCollection 2016.
8. St. Pierre, Brian.  Workout nutrition, explained. What to eat before, during, and after exercise. 
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