There are dozens of options! How do you know which one to try?!
What is a sports drink?
TLDR: A sports drink is designed to be consumed during exercise lasting 90 minutes or longer. Anything up to 60-75 minutes and you’re probably good with water. The only caveats here are if you’re hungry going into exercise, you’re already dehydrated, or it’s crazy hot.
What’s in a sports drink?
Water. What, you thought it was alcohol? Sorry!
Why is water required? Dehydration can be dangerous. Even if it’s not dangerous, it makes your training sessions feel harder. The smaller blood volume makes the heart have to beat faster to deliver the same amount of oxygen to muscles. Why make your training harder than it needs to be?!
Carbohydrates
Why consume carbs?
You don’t have to. But for longer exercise sessions (anything over 90 minutes), the carbohydrate helps keep blood glucose levels stable. Many people worry about carbs during exercise because they don’t want their blood glucose levels to go UP, but eventually they will go DOWN. And then the wheels come off and you will be miserable. This is why marathoners drop out of races and team sport athletes don’t have energy at the end of games. Shorter training sessions of high intensity training can also have this effect. Taking in carbs during training can keep blood glucose levels from dropping too much.
How much carbs do you need?
How much carbohydrate is needed? Carbohydrate is provided in a range of 4-8% wt/vol.1,2 Weight/volume, or wt/vol, is measured in grams/liter for sports drinks. 4% wt/vol is equal to 40 grams of carb per liter. So a sports drink generally provides somewhere between 40 and 80 grams/liter, sometimes a bit more. This range generally doesn’t cause upset stomachs, nausea or diarrhea.
What carbs are in a sports drink?
As an example, the popular sports drink Gatorade has 14 grams of carbs/8 ounces, or 56 grams/quart. Converting this to liters, this is 6% wt.vol.
Glucose
Glucose is a significant part of the carb in any sports drink. It can be added as a single molecule or in short chains or longer starches. This is handy, since it is easily used by the body for energy!
Dextrose is two glucose molecules stuck together. Maltodextrin is a slightly longer chain, usually 8-18 molecules stuck together. They’re a good way to add carbs without a lot of sweetness in a sports drink.
Glucose Chains
Longer starches can also be used. They are similar to corn starch, but often come from different carb sources. Advantages of using these longer starches include almost no sweetness and very stable blood glucose levels.4 They’re also an option for those with sensitive guts, as the starch chain reads as one molecule to the gut as opposed to a large number of single molecules or short chains in the above options. Disadvantages include a very different mouthfeel and difficulty getting some starches to dissolve. Example: UCan.
There are also cyclic dextrins, which are branched rings of glucose. These also take a long time to dissolve and provide a muted sweetness but are also good for those with GI issues as above. Examples: Skratch, Klean
Fructose
Fructose is a slightly different shape and uses a different absorption mechanism. This different absorption system moves more energy from the gut into the body in less time. So it’s really common to see some combination of glucose and fructose in a sports drink.
Sucrose is glucose and fructose stuck together. You’d commonly see this as table sugar.
What is the ideal glucose:fructose ratio? Originally it was a 2:1 ratio, or twice as much glucose as fructose. Other research shows more of a 5:4 ratio, or using glucose for a little more than half of the total carbohydrate.3 Any sports drink will use some variation of this, often while claiming the best ratio!
Galactose
What about galactose? The eagle-eyed reader might have noticed that sports drinks don’t contain galactose. Galactose utilizes the same absorption and breakdown pathways as glucose and is either found as lactose – which many people can’t tolerate – or in chains – which we can’t break down. So there’s not much point in adding it to sports drinks!
Electrolytes
Electrolyte levels in sweat are not useful predictors of hydration status, sweat rate, exercise intensity or other components of performance or stress!5
Sodium
Sodium is the major electrolyte and cation in extracellular fluid. We need around 500 mg/day, but most people get much, much more – especially if they consume a lot of highly processed foods. It is needed for nerve conduction and muscle contraction and helps us retain body water. This is great if you’re sweating a lot from training or heat, but not great if you’re sedentary!6 Levels of sodium in sweat vary wildly, based on vagaries of diet and sweat glands.5 It is also the electrolyte in the highest levels in sweat – so the thing that might need replacement!
Potassium
Potassium is the major electrolyte and cation in intracellular fluid. We need between 2500 and 4000 mg/day, depending on age and sex. It’s required to balance sodium to keep a normal distribution of water in and out of cells, as well as the electrical charge on the cell wall between those bodies of water.7 Coconut water is “high in electrolytes,” but really it just high in potassium.
Magnesium and Calcium
Magnesium is found in sweat, but the amounts are indicative of free blood magnesium, not much else. We need between 310 and 420 mg/day, depending on age and sex.8 Learn more about magnesium and food sources here!
As with magnesium, calcium is found in sweat but it’s indicative of free calcium in the blood that’s not bound to proteins. It’s not really useful for assessments of status. We need between 1000 and 1300 mg/day.9
Levels of calcium and magnesium found in sports drinks are so minimal compared to our needs that they shouldn’t generally be considered sources of those nutrients.
Electrolyte-only or Low Carb/High Electrolyte Drink Options
Electrolyte-only sports drink options include Nuun and similar products, coconut water (potassium only), and a variety of electrolyte tablets/capsules (SaltStick, SaltStick Chews, elete water, Gatorlytes packets, Gatorade Zero powder, Pedialyte powder (low carbs, not no carbs), and Skratch Clear (again, low carbs, not no carbs).
When do you need a sports drink?10
Before exercise
If it’s hot, you’re thirsty, you’re hungry and you need the energy for the upcoming tough workout, you might consider having a sports drink. Food and water would also work there.
Hyperhydration, or preloading water and electrolytes or glycerolor creatine, is another possibility for long events in the heat. This is consuming large amounts of salty fluid in the hours or day before an event. This can lower body temperature a bit during exercise and delay dehydration and a reduction in sports performance. Real food options include a lot of brothy soup or miso soup before an event or water and salty foods like pickles or pretzels. Water and a sandwich made with lunchmeat and cheese or water and pizza might also be good. A sports drink would also help. It all depends on the individual athlete.
During exercise
The official guidelines are to go into your exercise or training hydrated, hydrate during and rehydrate after. The extent to which you do this will vary with the training session. If you need sodium or calories, a sports drink is a great option because as shown above, they’re specifically designed to be tasty and easily absorbed!
If required, or if planning for a long endurance race, sweat tests, sodium testing and other variables can be considered to craft a specific hydration strategy. How much sports drink to consume when is part of this!
After exercise
Rehydration can take up to a day or more if you get really dehydrated. It helps to know the signs and symptoms of dehydration, heat stress and heat stroke, and make a list of the specific issues YOU experience. How do you feel when you’re dehydrated? How often do you urinate? A sports drink can help with rehydration, especially if there’s sodium included!
Next Steps
If you have any personal questions or issues with hydration, please contact Dr. Schubert! Race day plan packages or hydration planning (including that sports drink!) can really make a long competition much more bearable!
Check out the environmental reasons why you might sweat and ways to lose body heat so you don’t need as much to drink! A list of magnesium sources always comes in handy, as does a list of sports drinks that provide sodium (and maybe some carbs) without a being sweet! Enjoy this snarky blog on cheering for an Ironman (which takes coffee, a sports drink or two, and a lot of snacks).
A Testimonial!
TESTIMONIAL: “Laurie has always been extremely helpful when I have needed it. She made suggestions for race preparations and race-day nutrition and hydration that got me through “Revenge at Racine in 17”, Chatta 70.3 this year, and other races. On a hot Sunday in Tennessee and Georgia, how to stay hydrated for maximum performance was one of many tips of hers that I followed. You may be surprised by how many people mess that up. If you do any type of long-distance endurance training or events, you should consult an expert in nutrition. If you are in or around Chicago, I cannot recommend Laurie highly enough.” -Chris Haaff, multi-time Ironman finisher
REFERENCES:
- Sutehall S, Muniz-Pardos B, Bosch AN, Di Gianfrancesco A, Pitsiladis YP. Sports Drinks on the Edge of a New Era. Curr Sports Med Rep. 2018;17(4):112-116. doi:10.1249/JSR.0000000000000475
- Von Duvillard SP, Braun WA, Markofski M, Beneke R, Leithäuser R. Fluids and hydration in prolonged endurance performance. Nutrition. 2004;20(7-8):651-656. doi:10.1016/j.nut.2004.04.011
- O’Brien WJ, Rowlands DS. Fructose-maltodextrin ratio in a carbohydrate-electrolyte solution differentially affects exogenous carbohydrate oxidation rate, gut comfort, and performance. Am J Physiol Gastrointest Liver Physiol. 2011;300(1):G181-G189. doi:10.1152/ajpgi.00419.2010
- Davitt PM, Saenz C, Hartman T, Barone P, Estremera S. Physiological Impact of a Single Serving Slow Absorption Carbohydrate on Metabolic, Hemodynamic, and Performance Markers in Endurance Athletes During a Bout of Exercise. J Strength Cond Res. 2021;35(5):1262-1272. doi:10.1519/JSC.0000000000003968
- Baker LB, Wolfe AS. Physiological mechanisms determining eccrine sweat composition. Eur J Appl Physiol. 2020;120(4):719-752. doi:10.1007/s00421-020-04323-7
- Terry J. The major electrolytes: sodium, potassium, and chloride. J Intraven Nurs. 1994;17(5):240-247.
- Potassium: Fact Sheet for Professionals. National Institutes of Health Office of Dietary Supplements. Updated June 2, 2022. Accessed June 14, 2022. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/ – h5
- Magnesium: Fact Sheet for Professionals. National Institutes of Health Office of Dietary Supplements. Updated June 2, 2022. Accessed June 14, 2022. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ – h2
- Calcium: Fact Sheet for Professionals. National Institutes of Health Office of Dietary Supplements. Updated June 2, 2022. Accessed June 14, 2022. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
- Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance [published correction appears in J Acad Nutr Diet. 2017 Jan;117(1):146]. J Acad Nutr Diet. 2016;116(3):501-528. doi:10.1016/j.jand.2015.12.006