If you’re grabbing a sports drink to replenish your electrolytes after exercise, you could actually be working against your workout.

A CBC Marketplace investigation found that the vast majority of Canadians don't exercise hard enough to need the colourful drinks, and an average workout does not deplete the body enough to require additional energy and electrolytes.

“The benefit of getting physically active – [which] improves your body composition, makes you healthier, makes you fitter and all that – that’s fantastic, but unfortunately, drinking sugary, salty drinks actually does the opposite to the average person,” sports physiologist Dr. Greg Wells told Marketplace co-host Tom Harrington.

WATCH Marketplace's episode Farther, Faster, Fitter? airs Friday at 8 p.m. (8:30 p.m. in N.L.). Follow the conversation on Twitter by using the hashtag #sportperformance.

What’s more, sports drinks can be high in sugar and sodium. Gatorade’s Glacier Cherry Perform drink contains 41 g of sugar per serving -- more than 10 teaspoons of sugar -- and 330 mg of sodium, more than a McDonald’s medium fries and more than a serving of Doritos Cool Ranch chips.

Marketplace teamed up with Canadian Olympians Clara Hughes and Simon Whitfield to investigate popular products -- including sports drinks, protein bars and high-tech running shoes -- that promise to enhance athletic performance. The full investigation, Farther, Faster, Fitter? airs Friday at 8 p.m. (8:30 p.m. NL) on CBC Television.

Performance product trials

Sports drinks promise to rehydrate, provide energy to muscles in the form of sugar and replenish electrolytes lost during exercise. Canadians guzzle more than $450 million in sports drinks every year.

Popular choices such as Gatorade are extensively promoted for their ability to help athletes refuel. Gatorade boasts their beverage is “scientifically formulated” and will “provide optimal quantities of sodium, potassium and carbohydrate to support exercise.” Powerade promises an “advanced electrolyte system designed to help replenish four electrolytes lost in sweat.”

Electrolytes are minerals, such as potassium and sodium, that carry an electrical charge and are important for body function. They can be depleted through sweat during intense exercise over a long period of time or in the hot sun.

Canadian Olympic medallist Simon Whitfield joined CBC Marketplace’s investigation on sports performance products, including sports drinks, protein bars and high-tech running shoes. (CBC)

To test how many electrolytes are actually lost during exercise, Marketplace recruited a team of recreational runners and tested their blood before and after a 45-minute run. None of the runners depleted either their glucose or electrolyte levels enough to require a sports drink to replenish them. In many cases, electrolyte and glucose levels increased in the blood. The test revealed that they could have benefited from water alone.

Wells, who is a researcher with the Human Physiology Research Unit at the University of Toronto and has worked with elite athletes, says that the body is very good at providing itself with what it needs to fuel moderate exercise.

“Your body is very, very good at making the changes it needs to make in order to keep you exercising safely all on its own,” he says.

Marketplace also tested the blood of an elite triathlete during intense cycling and discovered that it would take about two hours of strenuous activity before she would benefit from the electrolytes in a sports drink.

Sports drinks popular with kids

Promoted by professional sports stars such as Sidney Crosby and LeBron James, sports drinks are a popular choice among young athletes.

The Canadian Paediatric Society recommends the use of sports drinks for young athletes when they are exercising in intense heat and humidity or for longer than 60 minutes, but it also cautions against overuse.

“For non-athletes, routine ingestion of carbohydrate-containing sports drinks can result in consumption of excessive calories,” the group warns, “increasing the risks of overweight and obesity, as well as dental caries and, therefore, should be avoided.”

Wells cautions that younger kids shouldn’t be using sports drinks for normal sports activities. “We know that children don’t sweat as much as adults do,” he says. “So, they don’t actually need it as much as adults do. And kids’ events are typically shorter and not long enough to require them. We’re giving our kids a lot of sugar, lots of salt, so we need to be very, very careful with that.”

Helpful for intense exercise only

“Sports drinks are marketed as beverages formulated for athletes and those who are physically active,” the Canadian Beverage Association (CBA) wrote in a statement to Marketplace.

Canadian Olympic medallist Clara Hughes teamed up with Marketplace to investigate the claims behind popular sports performance products. (CBC) “Hydration is essential for good health, and science shows that the water, carbohydrates and electrolytes in sports drinks provide significant hydration and athletic performance benefits for active individuals.”

The CBA also notes that sodium in sports drinks is an electrolyte that helps enhance fluid absorption, and while many drinks do contain sugar to fuel muscles, many companies “also provide a wide variety of low and no calorie hydrating beverages so that consumers can choose the product that is right for them depending on activity levels and caloric needs.”

Wells agrees, to a point. “Sports drinks are fantastic for keeping electrolytes levels well, rehydrating you and giving you sugar that you need to exercise,” he says. “But the average person, in a gym, typical spin class, yoga class, going to lift some weights, you need water.”

Wells says that while sports drinks are widely available, they’re only really helpful to a small minority of athletes. “Eighty-five per cent of Canadians don’t get enough exercise to begin with, so they don’t need sports drinks. The remaining 15 per cent that actually do exercise, you probably have one or two per cent exercising really hard, really intensely enough to really need those sports drinks. In that group, probably a small subset of them are exercising long enough to need it.”

“In the scientific community, we generally don’t recommend sport drinks for anything less than 90 minutes, if you are exercising really intensely, if you are exercising in the heat, if you are exercising for a very long period of time.”

Wells says most of us are better off with water. “An average person like you, during a workout, you need to be drinking a lot of water; that’s pretty much all your body needs. That’s what your body needs for your muscles to work really, really well. That’s what your blood needs to circulate really well.”