WHY YOU CAN’T OUTRUN YOUR ELECTROLYTES AND WHY WATER ALONE WON’T SAVE YOU ON RACE DAY
By Perez-Maymi
This article revisits a topic I discussed in a previous article several years ago. It was the basis for a recent conversation I had with several of our runners during a training session.
Many runners express a common complaint: “I dislike the electrolyte mixture during races and don’t take it during training.” This is understandable. The taste, the stomach slosh, and the sticky sweet gels can be unpleasant. However, skipping electrolytes isn’t just about personal preference; it’s a performance and safety issue that becomes more significant as you run harder and longer.
Here’s why coaches and sports dietitians insist on the importance of electrolytes:
1. Water alone is insufficient. Scientifically proven, you lose more than water when you sweat. When you sweat, you lose blood volume that consists of water and electrolytes, primarily sodium, with smaller amounts of potassium, magnesium, and chloride.
These minerals play a crucial role in maintaining your energy levels during exercise. Let’s examine each one individually:
Sodium: It controls fluid balance and helps your nerves transmit signals to make muscles contract. Losing too much sodium can cause your brain to swell, muscles to cramp, and coordination to deteriorate.
Potassium and Magnesium: They regulate heart rhythm and muscle relaxation. Low levels of these minerals can lead to cramps, twitching, and fatigue.
Chloride: It works in conjunction with sodium to maintain fluid balance.
If you only replace water, you dilute the remaining sodium in your blood, leading to a condition called hyponatremia. Hyponatremia can cause nausea, confusion, and in severe cases, it can be a medical emergency. It’s the reason why you can drink a lot of water and still feel worse.
Now, let’s address the next question: Do you need electrolytes for every distance?
The answer depends on several factors, including the duration of the run, the heat, and the amount of sweat you produce. Each runner has different needs based on their sweat production.
For a 5K (under 45-50 minutes), most runners in cool weather can usually get by with plain water. However, if the temperature is over 75 degrees, it’s humid, or you’re a heavy sweater, a small amount of electrolytes can help you feel stronger at the finish.
For a 10K (45-90 minutes), this is where things get a bit tricky. You’ll lose a significant amount of sodium during this distance. Water is okay for a short, cool 10K, but if you’re out there for over an hour, you should be taking electrolytes.
For a Half Marathon (1.5 - 3+ hours), you absolutely need electrolytes. Glycogen depletion and sodium loss can cause you to hit the wall, cramp, and slow down dramatically in the last 3 miles if you don’t replace them.
For a Full Marathon (3 - 6+ hours), this is non-negotiable. Your body can’t store enough electrolytes for 26.2 miles. A proper hydration plan with both water and electrolytes is part of your race equipment, just like your shoes.
3. What About Speed Work in Zone 4-5 on the Track?
This is where runners often get caught off guard. Zone 4-5 is your threshold to reaching VO2 max at a fast, hard pace with a high heart rate.
Even though the workout is short, you’ll be sweating at your highest rate, your breathing will be heavy, and you’ll be burning through electrolytes quickly. You might not feel dehydrated during the 400m repeat, but you’ll definitely feel it afterward. You may experience headaches, muscle cramps at night, heavy legs the next day, and poor recovery.
Coaches refer to this as “hidden dehydration.” While you don’t necessarily need to sip a sports drink during the interval, what you drank 2-3 hours before and what you drink immediately after to recover is crucial. If you’re engaged in marathon speed training intervals, make sure to drink during recovery periods.
If You Hate The Mix On The Course, What Can You Do?
You don’t have to force yourself to drink the race-provided drink if you hate it. However, you do need to have a plan.
1. Train Your Gut Like You Train Your Legs: Avoid introducing new electrolyte products on race day. If you skip electrolytes during training, your stomach won’t develop the ability to tolerate them during a race. Begin with low-concentration mixes during training.
2. Find Your Form: Electrolytes are available in various forms, including capsules, tablets, chews, and low-sugar powders. Many runners who dislike sweet drinks find success with an electrolyte capsule and water.
3. Pre-Load: Hydrate with water and electrolytes the day before and morning of the race, not just during the event.
4. Test Your Sweat: If your clothes have white salt stains, you experience frequent cramps, or you crave salt, you may be a salty sweater and require more electrolyte replacement than the average person.
Bottom Line: While you may dislike the taste, your body cannot function without these essential minerals. For any effort exceeding 60 minutes or any intense effort in hot conditions, water and electrolytes are the standard for safe and effective performance.
This information is provided for educational purposes only. If you have a history of cramping, high blood pressure, kidney issues, or are taking medications that affect fluid balance, consult with your doctor or a registered sports dietitian to develop a personalized hydration plan that suits your individual needs.
Boogie Down Bronx Runners is committed to promoting health, wellness, and fitness. Remember, run smart.