Rebecca Toutant, MA, RD, CSSD, LDN, CEDS, CDCES, cPT

Summer is upon us in New England. That means soaring temperatures, sunshine, and plenty of humidity.

​With all of the hot weather, when do you need to start adding a sports drink instead of plain water? Read on for the answer…

Sweat is the body’s way of cooling itself. When the sweat evaporates from the body, it causes a cooling effect. Sweat is not just water – it also contains minerals called electrolytes.

​Electrolytes are essential to the body, they…

  1. Maintain fluid balance
  2. Help muscles contraction and relax 
  3. Essential in neural activity

The major electrolytes lost in sweat include sodium and chloride. Calcium, potassium, and magnesium are also affected by sweating. 

Medical conditions such as kidney disease / failure, diabetes, laxative abuse, and diuretics make it harder for the body to balance water and electrolytes. Thee majority of people eating a balanced diet and staying hydrated, the body can balance out electrolytes without supplementation. However, when you lose a lot of fluid quickly (eg, sweating, diarrhea, vomiting), the body benefits from supplementation.

This article does NOT address fluid losses due to illness, diarrhea, or vomiting. It is also NOT applicable for diabetics that take insulin or sulfonylureas (eg glipizide). Remember that every person is unique. This article is meant as general guidance. For specifics, reach out and we can come up with a plan for your unique needs. ​

Who needs a sports drink?

Sports drinks are designed to: 
1.) Provide energy to continue a workout and/or
2.) Replace electrolytes lost due to sweat

You may want to use a sports drink if you are…

Exercising intensely

  • If you plan to work hard >1 hour (but less than 2 hours) you can get away with a little sugar and water. The glucose (sugar) in the sports drink helps fuel the exercise but electrolytes are less of a concern at this point (unless you’re a very heavy sweater or it’s very hot…Most people think they sweat a lot, however when I’m talking about a heavy sweater, I’m talking about people who have residue / crystals on their skin after sweating). 
  • If you plan to work hard >2 hours (regardless of temperature), you may want to introduce something with sugar and electrolytes starting at the 1 hour mark​

 
Exercising in very hot weather

  • The hotter the weather, the more you are going to sweat! If you’re going to be sweating heavily over an hour, consider adding a sports drink

How much / how often should I drink?

It depends. For people using it as fuel, your body needs and can absorb ~15 grams of carbohydrate every 20-30 minutes (usually ~8 oz of a drink). Depending on the intensity of the exercise and the heat of the day, the absorption rate can go up or down. That means over the course of an hour, you might have 16 oz of a sports drink. 

It’s important to STILL include water when you’re exercising intensely or in hot weather because the stomach can’t absorb excessive amounts of glucose in those conditions. If you don’t include water, you’re more likely to have stomach  problems such as cramping and diarrhea.  

Sports drinks tend to dial in their formulas to meet the best absorption rate. Follow the recommended fluid to powder ratio (and resist the urge to water it down). 

What about AFTER exercise?

Ideally you don’t complete your exercise severely dehydrated (because you’ve been fueling and hydrating along the way….). But if you are done exercising and need to recover moderate electrolyte losses, it’s best to get your electrolytes from real food and water as much as possible. Yogurt with berries along with some pretzels replace lost energy and electrolytes and help your muscles repair. Water is usually sufficient to replace fluid losses. If you can’t stomach solid food, making a smoothie is the next best bet. 

What should I buy?

There are a lot of different products on the market. What you choose depends on your taste preferences, budget, and glucose needs. Personally, I enjoy Scratch Labs because 1.) It’s easy on my stomach and 2.) It doesn’t taste super sweet like other formulas (I get “sugared out” on long runs/rides).

Common brands include: GatoradePoweradeScratch LabsHammerNuun

Should I get a “sugar free” sports drinks?

Sugar gets a bad reputation. Sugar is a rapidly digested form of carbohydrate. Athletes NEED it and people who are dehydrated also need it. But keep in mind if you’re not in those 2 categories, a sports drink might not be the right decision for you. 
​Are you trying to replace lost electrolytes –>CHOOSE SUGAR!. Your body NEEDS glucose (aka sugar) in order to adequately absorb the electrolytes. 

Are you trying to fuel your activity –> CHOOSE SUGAR!
​The glucose IS the fuel.

You want something that tastes good –> Sugar free is fine. Keep in mind that a 20 oz Gatorade has ~34 g sugar (~8-9 teaspoons)

Should I take a pill?

​​For the average person, there is RARELY a need to take a pill of any one particular electrolyte unless instructed to do so by your medical provider. Taking too much of some electrolytes (eg, potassium) can be FATAL.

However, for endurance athletes that are 1.) Doing events >2 hours and / or 2.) Working in very hot conditions, an electrolyte tablet (aka “tab”) may be helpful. Tabs are higher doses of electrolytes in balanced amounts. However, the only reason to choose a tab at this point instead of a drink is because the stomach cannot tolerate and absorb the necessary volume of water + glucose + electrolytes. 

In short…

  • hydrate early and often
  • if you’re going to be out there a long time and/or sweating a lot, add sugar and electrolytes either from a drink or solid foods

Stay hydrated out there!