Electrolytes during exercise: Plan B
In the critically-acclaimed move “Idiocracy”, the characters discuss the value of electrolytes. It’s the year 2505, and plants are being watered with a sports drink called “Brawndo” because “It’s got electrolytes”. One character suggests that the plants just need water to survive, but no one else seems to agree. They are all convinced that electrolytes are what plants need to grow, simply because that’s what they’ve been told. Electrolyte consumption for humans during exercise seems a bit more logical, but often its importance is overstated.
Overstatement #1: Drinking a sports drink during exercise will prevent hyponatremia
In my post about hydration during exercise, I talked about exercise-associated hyponatremia. This potentially life-threatening situation arises when too much fluid moves into your body’s cells (particularly brain cells), causing them to swell. A major determinant of body fluid movement is the concentration of sodium in your body. When you start to sweat during exercise, the concentration of sodium in your bodyincreases. It’s like if you start to boil a pot of salt water: The water boils off and you’re left with a more concentrated salt solution. Now think about adding some water to that pot. When you drink water, you bring the concentration of sodium back down. But if you drink too much water, the concentration of sodium gets too low, and you run into problems. A recent study of runners at the London Marathon showed that 12% of athletes planned to drink enough to risk hyponatremia.
So will drinking a sports drink instead of water help you avoid the development of hyponatremia? Maybe.
The concentration of sodium in a sports drink is A LOT lower than in your body, so drinking too much sports drink can still dilute your blood sodium and result in hyponatremia.
What’s a better Plan A? Don’t gain weight during your long runs. Research shows that if you’ve gained weight during a long run, you’re at greater risk of hyponatremia. Whether you prefer to drink water, sports drink (there are other benefits to taking in a sports drink), or something else, just ensure that you don’t drink enough to gain weight. After this, Plan B can be to drink a sports drink or take in some additional sodium in order to help your body control its sodium levels a bit better. Individual sweat sodium concentration should also be considered. Athletes can lose between 500 and 2,000mg of sodium per litre of sweat, so some athletes may benefit more than others from sodium intake.
Overstatement #2: Taking in electrolytes during exercise will prevent or relieve muscle cramps
This topic is less cut and dry, and there’s lots of good debate to be had here, but I’m not going to delve too deep. A lot of researchers say the cause of most muscle cramps is simply muscle fatigue. Other researchers say that improper electrolyte balance is to blame in some cramping situations. Many athletes believe that taking in electrolytes helps them avoid cramping, or that if they did cramp during a run, it was because of insufficient electrolyte intake. In general, the effectiveness of electrolyte intake for preventing muscle cramping is overstated. Just like with electrolyte intake and hyponatremia prevention, there is a better Plan A: Proper training and pacing. But if you feel you have covered those bases and you’re still having problems, then having electrolyte intake as a Plan B may help.
Overstatement #1: Drinking a sports drink during exercise will prevent hyponatremia
In my post about hydration during exercise, I talked about exercise-associated hyponatremia. This potentially life-threatening situation arises when too much fluid moves into your body’s cells (particularly brain cells), causing them to swell. A major determinant of body fluid movement is the concentration of sodium in your body. When you start to sweat during exercise, the concentration of sodium in your bodyincreases. It’s like if you start to boil a pot of salt water: The water boils off and you’re left with a more concentrated salt solution. Now think about adding some water to that pot. When you drink water, you bring the concentration of sodium back down. But if you drink too much water, the concentration of sodium gets too low, and you run into problems. A recent study of runners at the London Marathon showed that 12% of athletes planned to drink enough to risk hyponatremia.
So will drinking a sports drink instead of water help you avoid the development of hyponatremia? Maybe.
The concentration of sodium in a sports drink is A LOT lower than in your body, so drinking too much sports drink can still dilute your blood sodium and result in hyponatremia.
What’s a better Plan A? Don’t gain weight during your long runs. Research shows that if you’ve gained weight during a long run, you’re at greater risk of hyponatremia. Whether you prefer to drink water, sports drink (there are other benefits to taking in a sports drink), or something else, just ensure that you don’t drink enough to gain weight. After this, Plan B can be to drink a sports drink or take in some additional sodium in order to help your body control its sodium levels a bit better. Individual sweat sodium concentration should also be considered. Athletes can lose between 500 and 2,000mg of sodium per litre of sweat, so some athletes may benefit more than others from sodium intake.
Overstatement #2: Taking in electrolytes during exercise will prevent or relieve muscle cramps
This topic is less cut and dry, and there’s lots of good debate to be had here, but I’m not going to delve too deep. A lot of researchers say the cause of most muscle cramps is simply muscle fatigue. Other researchers say that improper electrolyte balance is to blame in some cramping situations. Many athletes believe that taking in electrolytes helps them avoid cramping, or that if they did cramp during a run, it was because of insufficient electrolyte intake. In general, the effectiveness of electrolyte intake for preventing muscle cramping is overstated. Just like with electrolyte intake and hyponatremia prevention, there is a better Plan A: Proper training and pacing. But if you feel you have covered those bases and you’re still having problems, then having electrolyte intake as a Plan B may help.
