Nutritional Value Of Isotonic Sports Drinks

An exercise or a workout turns on your sweat glands, your heart rate and blood pressure causing the body to heat up. To regulate body temperature, you produce sweat. Sweating is the body’s response to the rise in temperature, to stabilize it to a normal range. As you sweat it out with repeated and long periods of exercises such as biking and running, it causes your electrolytes to decrease drastically to a dangerous level.

What causes electrolytes imbalance? In this case, the hypothalamus in the brain triggers the release of water that carries sodium chloride, and other electrolytes such as potassium, magnesium, and calcium. As the water in the form of sweat evaporates from the skin, it takes some of the heat with it and cools down your body. At the same time, as you continue sweating, you lose minerals that are essential for your body’s metabolism.

There are several ways to replenish lost electrolytes and fluid, but the easiest is to take isotonic sports drinks. They are commercially formulated beverages for those who engage in sports and rigorous physical activities. You can buy them as bottled fluid, powder in sachets, or tablets which you add into a measured amount of water. Sports drinks help rehydrate and replace electrolytes during long duration exercise, especially in the heat.

What Do They Contain?

Isotonic sports drinks are high in simple carbohydrates and sodium. They also contain other electrolytes such as potassium, magnesium, chloride, and calcium. The concentrations of salts and sugars are similar to those in the human body, so they quickly replace what you have lost. Typical ingredients of an isotonic sports drink include food acid, electrolytes, additive, coloring, flavoring, sweetener, vitamins, acidity regulators, and more.

Electrolyte contents of an isotonic sports drink may compose of sodium bicarbonate, sodium chloride, calcium carbonate, potassium chloride, tri-calcium phosphate, and magnesium carbonate. Vitamins can be in the form of pyridoxine hydrochloride, riboflavin, and thiamin. It has food acid such as citric and malic with acid regulators such as tri-sodium citrate and potassium citrate.

An isotonic sports drink may contain maltodextrin, the sweet white powder from corn, rice, potato, and wheat used as a food additive. It might also have sucralose, an artificial sweetener, and sugar substitute. The ingredients may include sorbitol and inulin. Sorbitol is a sweet tasting sugar alcohol which the body metabolizes slowly. The dietary fiber inulin, on the other hand, is a complex sugar which belongs to the class known as fructans.

If you have allergies and certain food intolerance, you can buy them lactose-free, gluten-free, wheat-free, nut-free, and soy-free. There are sports drinks which do not have artificial colors, preservatives or sweeteners, that only use natural flavorings and colorings such as blackcurrant, raspberry, strawberry, blackberry, and blueberry.  There are several products on the market which cater to your specific needs so check the labels: ingredients, nutrition values, and allergens.

What Are The Benefits?

Isotonic sports drinks have the same osmotic pressure and the correct electrolyte ratio as the body fluid.  So, they offer a fast and efficient source of simple sugars which are absorbed by the body without difficulty to fuel you up and renew your energy. These beverages help your muscles continue to function normally especially if you’re doing heavy exercises that last for 45 minutes or more.

As an endurance athlete, you need to rehydrate and replenish the lost electrolytes in your body during and after the workout to avoid fatigue, tiredness, lethargy, fast heart rate, nausea, constipation, vomiting, and seizure to some extent.  Isotonic sports drinks are the best beverages when going for a run or cycle, playing sports (tennis, soccer, hockey, football, basketball) or weight-lifting.

How isotonic sports drinks energize you? Since it generally contains 4 to 8 grams of sugar per 100 ml, it is taken up by the body the same way as water. It rehydrates you and tops up electrolytes and other nutrients rapidly thus enhance your performance level. When you need an extra push to keep going longer and stronger, you should take isotonic sports drinks particularly when the weather is hot and humid.

What Are The Negative Effects?

Keep in mind that isotonic sports drinks have high sugar contents, so if you have diabetes and insulin resistance or want to lose weight, you should include drinking isotonic sports beverages in your total carbohydrate count for the day. It can spike your blood sugar levels and cause headaches, weakness, feeling of tiredness, stomach pain, blurred vision, frequent urination and increased thirst.

Sorbitol, a sweetener of some sports drinks also acts as a laxative which is poorly absorbed by the small intestine. Excess sorbitol intake of more than 50 grams is dangerous and can cause abdominal discomfort, gas, stomach cramps, weakness, and dizziness.  As a laxative, it draws water into the large intestine which in turn stimulates bowel movements, so you have frequent urge to go to the toilet.

Another ingredient that you need to watch out for is the dietary fiber inulin which is not digested and absorbed in the stomach but goes to the large intestine.  When bacteria ferments it in the large intestine, it causes the production of gas.  In turn, the gas production causes symptoms such as bloating, flatulence, stomach pain and diarrhea. So, be sure to read the labels and understand the function of each ingredient.

Some isotonic sports drinks have sucralose, an artificial sweetener. Your body does not break it down into energy like the simple sugars. According to Medical News Today, “consuming too much of an artificial sweetener may cause diarrhea, bloating, gas, or have a laxative effect in some people. There is also the possibility of an allergic reaction, so it is important to pay attention to any changes in the body.”

Should You Limit The Intake?

Water is enough to sip-on before and during the warm-up or if you’re not doing intense and long workouts. But when the game or workout begins, and you feel the sweat coming out, you should take isotonic sports drinks.

Our recommended way of doing this is small regular sips every few minutes. If you go for a run or cycle, then check out our hydration belt reviews for some recommended simple products.

How much is your limit? It depends on the amount of your sweat and the actual condition such as temperature and humidity. If you don’t have health issues, you can follow these tips:

  • Take about 5 to 7 ml per kilogram body weight which means if you weigh 60 kilograms you drink from 300 ml to 420 ml or approximately 1¼ cups to 1¾ cups isotonic sports drink.
  • Increase your intake when you sweat a lot especially when you’re outdoors in the heat and you wear sports equipment like in hockey and football.

If you have concerns, better consult first your physician before taking isotonic sports drinks. Always check the labels and verify the safety of each ingredient. Your performance has a direct relationship to what you eat and drink. So, if you want to be at the top of your game, choose your sports drinks wisely and regulate them based on your daily nutrition intake value.


Hi, my name is John Turner, and I’m the IT and baseball geek behind this website. Professionally I specialize in online security systems for financial transactions. Sounds incredibly boring to most people, which is why I focus on baseball when I’m at parties.

I think I met everyone involved in this site through Little League where our kids have been involved over the years. I’m one of the many coaches, and have an absolute passion for everything to do with baseball.

Ever since I got my first baseball card at about 5 years old, I’ve been addicted to all types of baseball statistics. The others keep winding me up when I give them the exact numbers from past seasons and games. Maybe it’s a super-power or maybe I’m just a bit too much of a nerd.

Coaching young kids and seeing them develop the same passion for the game is just so much fun, that it literally is the highlight of my week. I’ve met so many parents in our community this way, and it’s wonderful seeing these young kids growing up with the sport.

Anyway, I contribute on this site for anything baseball related as well as some fitness tips for kids and adults. I’ve done quite a few courses on coaching kids and adults and have learned so much over the years that I want to share with a much bigger audience.

We will be happy to hear your thoughts

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