Electrolytes are much more than a buzzword thrown around in your running group – they serve critical purposes for your body during runs and everyday life. Discover why you need them and when you should be incorporating them into your workout routine.
Disclosure: This post was sponsored by NOW®. As always, all opinions are my own.
Disclaimer: This post was written and reviewed by Chrissy Carroll, MPH, RD, RRCA Running Coach. It is for informational purposes only. Consult a doctor or dietitian when considering a change in your diet or supplementation routine.
What are electrolytes?
In the nutrition world, electrolytes refer to minerals that carry either a positive or negative electrical charge when dissolved in water. They are essential for regulating the amount of water in your body, muscle contractions, nerve impulses, maintaining acid-base balance, and other important functions.*
Why are electrolytes important for runners?
Because electrolytes are key for muscle contractions and fluid balance, it makes sense that they would be quite important during a run.* Plus, when you run your body loses electrolytes through sweat.
If you fall low in certain electrolytes over the course of a long run, it may contribute to muscle cramping and fatigue in some athletes.* However, this is not true for every athlete – neuromuscular fatigue and genetic predisposition may play more of a role in muscle cramping than electrolyte balance. [Read this post about muscle cramps in runners for a much deeper dive into this topic!].
Key electrolytes for runners
Here are the common electrolytes that runners should know about:
Sodium
Sodium is the most abundant electrolyte your body, and probably the most important one for runners to focus on. It helps to regulate fluid balance and plays a role in muscle contraction.*
While too much sodium in your everyday diet can negatively affect health, it’s important for runners to make sure they are getting enough during exercise since it’s the most prevalent electrolyte lost in sweat.
Losing too much sodium during an event may put you at greater risk for issues like cramping or early fatigue.* Though research is contradictory on cramping during exercise and sodium – “heavy salt sweaters” may anecdotally find benefit in upping their sodium intake during long sessions.*
Sodium in sports drinks also helps to stimulate your thirst mechanism, helping you maintain better hydration balance.* This is important since losing more than 2-3% of your body weight can negatively impact performance on your runs.
(On the flip side, it’s also important not to overhydrate during exercise, which can dilute blood sodium levels and cause a dangerous condition known as hyponatremia.)
Potassium
Potassium is important for heart health and muscle contractions.* You should aim to get ample potassium each day through your regular diet, through foods like fresh fruits and veggies (hello, bananas and potatoes!), milk, yogurt, beans, and some meat and fish.
During exercise, you do lose a small amount of potassium through sweat. Athletes participating in long distance or ultra events may want to pay attention to potassium in their beverage or fuel, as the losses through sweat could add up over the many hours of running.
Calcium
Calcium is critical for muscle and nerve contractions and managing your heart’s rhythm.* As a mineral in our body, it’s also important for bone health (very important for runners who are at risk for stress fractures).*
Runners should aim to get enough calcium in their everyday diet through sources like dairy, leafy greens, sardines, almonds, and fortified foods.
Calcium losses are not usually a major issue during exercise as only a small amount is lost through sweat.
Magnesium
Often overlooked, magnesium is an electrolyte involved in muscle and nerve contractions.* In addition, as a mineral in the body it’s involved in energy production and enzymatic reactions, and magnesium may also play a role in running recovery or muscle health.*
You can get enough magnesium in your diet by including foods like nuts, seeds (roasted pumpkin seeds are one of my personal favorite sources), spinach, dark chocolate, beans, oats, quinoa, and other foods.
The amount of magnesium lost in sweat is much lower than the amount of sodium and potassium.
Electrolyte strategy for runners
The first part of a successful electrolyte strategy is ensuring you’re meeting your needs for calcium, magnesium, and potassium in your everyday diet. The foods described in the section above are a great way to do that.
If you don’t get enough of these nutrients in your diet (which can be common with magnesium and calcium), you can consider a supplement to meet your needs. I’m a fan of NOW® Calcium & Magnesium Softgels (which also contains Vitamin D and zinc). It’s a great option for a daily supplement if you can’t meet your needs through diet alone.
When it comes to electrolytes on your actual runs, you’ll want to primarily focus on sodium since it’s lost in the highest amounts in sweat.
It’s difficult to give general recommendations for sodium intake, though. The rate that you sweat, and how much sodium is in that sweat, is influenced by factors like genetics, body weight, heat acclimatization, and the intensity of exercise. For example, research shows athletes may lose anywhere from 0.5 liters to 2 liters of sweat per hour!
As a starting point, the ACSM Position Stand on Exercise and Fluid Replacement notes the IOM guidance of 20-30 mEq sodium and 2-5 mEq potassium per liter as a baseline for sports drinks. This translates to 460 mg to 690 mg of sodium and 80 to 200 mg potassium per liter.
However, heavy sweaters or folks exercising for a long time in hot conditions may need a bit more than these ranges. (As someone constantly covered in salt on my skin after a workout, I aim a bit higher on that electrolyte.)
To ensure you’re meeting your electrolyte needs during and after a run, consider these guidelines:
- For runs over an hour, consume a sports drink or electrolyte drink that contains adequate electrolytes (i.e., meets the recommendations above, or a bit higher than those for heavy sweaters) during your run, and replenish fluid and electrolytes after you run as needed.
- For intense runs that are less than an hour but take place in high heat, try consuming an electrolyte drink during or after your run.
- For runs less than an hour in moderate temperatures, plain water is typically all you need.
One of my personal favorite products for runners are the NOW® Effer-Energy effervescent electrolyte tablets.
These can be used during or after exercise, and I like the products for several reasons:
- Each tab provides 360 mg of sodium and is meant to be dissolved in 16 ounces of water. When extrapolated per liter, this is around 740 mg, so great for salty sweaters.*
- The tabs provide potassium to support the losses in sweat.*
- The tabs provide small amounts of calcium and magnesium to support the small losses in sweat.*
- This product is portable and easy to travel with! Just mix it into a water bottle when you’re training at your destination.
- The tropical punch flavor tab also has caffeine, which can impact performance during endurance exercise.* I like drinking coffee before a run to get enough caffeine for performance boosting benefits, then using these tabs to keep a bit of caffeine flowing during the run.* However, if your GI system sensitive to caffeine, you can skip over this. The other electrolyte tablet flavors like lemon lime, mixed berry, and orange strawberry do not have caffeine.
You can grab these electrolyte tablets or any other NOW® product using code CHRISSY for 20% off!
The Bottom Line
Electrolytes are essential for runners, as they help regulate fluid balance and keep your muscles functioning properly.* Be sure to get adequate amounts of potassium, calcium, and magnesium in your everyday diet. During runs, the primary electrolyte lost in sweat is sodium, so be sure this is in whatever electrolyte product you choose. If you’re struggling with your fueling or hydration, be sure to consult a dietitian for personalized advice.
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.
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