When U.S. gold medal swimmer Michael (The Flying Fish) Phelps pierces the surface of the pool like a bullet at the Rio Olympics, millions around the world will be watching.

Phelps has broken multiple world records and continues to inspire young athletes to push the limits, but do world-class Olympians inspire fans and everyday people to get more active?

Dean Kriellaars says the opposite is true: winning more Olympic medals strongly correlates with a rise in obesity rates, at least in Canada.

Kriellaars, an associate professor at the University of Manitoba's Rady Faculty of Health Sciences, was interested in seeing whether there was any relationship between the Olympics and activity levels in the general population.

One of the big questions guiding his research was if a country like Canada wins more and more medals over time, how is that rise reflected in the fitness levels of the masses?

American swimming phenom Michael Phelps, shown here at the Beijing Games, returns for his final Olympics in Rio. (File/The Associated Press) Kriellaars studied each Olympics over the past 45 years and noticed "a straight line increase." Canadian athletes went from winning five medals at the 1972 Munich Games to 43 medals between the 2012 London Summer Games and 2014 Winter Olympics in Sochi.

He then measured obesity rates in Canada over the same time period and noticed a similar upward trend.

"If you look at that, you say, 'Hey, if we were getting progressively better at the Olympics, and it is inspiring the population to maintain an active lifestyle, you certainly wouldn't see that relationship,'" Kriellaars said.

Conversely, Kriellaars said, you would believe it was a safe bet to say that increasing obesity rates in Canada wouldn't produce more Olympians.

"That's a good scientific statement," he said. "At the end of the day, if it was true, that you are inspiring more consistent, active, persistent lifestyles by having more Olympic success, you shouldn't have seen the obesity rates rise like that."

In terms of why the relationship between obesity and podium finishes exists, Kriellaars said there could be another rise that helps explain the growing tendency to sit and watch rather than get up and go.

"Now there's a screen everywhere," he said. "We have a situation where screens basically make you inactive, so now the viewerships are so large that we have more sport spectators than we have sport participants, and that's the problem."

The Rio 2016 Olympic opening ceremony is Friday night. (Buda Mendes, Getty Images)

Live broadcasts of the Games are now just a few clicks or swipes away.

The ubiquity of smartphone technology is making us an "inactive thrill, slow kill society," according to Kriellaars, which is one reason he won't tune in to the Rio Olympics.

"I love sport, I am a patriotic person, but I prefer to do sport," he said. "What attracts people is the thrill, and it is thrilling, but what's the alternative, in our society, is to get out there and do some hard work. We need to return [to] our love of the actual doing things."

For those who do plan to take in the Games, Kriellaars said one way to avoid becoming a couch potato is to choose a few specific events and watch them in moderation. For instance, watching every single heat of the 100-metre race might not be necessary, he said.

The same principles apply to professional sports outside of the Olympics, he added.

"If you're watching every single one of the Jets games, if you're watching every single one of the NFL football games, if you're glued to the screen constantly to watch every single Olympic event … you're taking a large amount of activity time away from people."

The Rio Olympics opening ceremony takes place Friday night.