The Health Benefits of Open-Water Swimming

Or, how I learned to love Lake Ontario.

At exactly 11:07 p.m. on September 8, 1954, a 16-year-old named Marilyn Bell took off from a log retaining wall in Youngstown, New York, and started swimming home to Toronto. The water was a chilly 21°C. The waves were 15 feet high. Eels bit her stomach and legs in the darkness; she fought them off with her fists. By dawn, she had covered more than 20 kilometres. By 5 p.m., she had about six to go. Pink flares cracked over the Canadian National Exhibition to guide her in, but the current kept pushing her west. Finally, a full 21 hours and 64 kilometres after leaving New York, Bell touched the concrete breakwater just off Toronto and entered the history books, becoming the first person to swim across Lake Ontario.

It was a big moment for Canada and the tenacity of teenage girls. It was also a big moment for swimming in Lake Ontario, which lost a whole lot of its lustre by the time I was Bell’s age, not quite half a century later. Although Toronto has done heroic work since the 1970s to stop sewage overflow from reaching the water, and although our beaches are among the world’s cleanest, locals have held onto a nagging suspicion that something filthy lurks in the lake. It’s why, as an adult, despite living a quick walk from the shoreline, I stick to the same outdoor city pools I grew up swimming in. My favourite remains the Sunnyside/Gus Ryder pool, a round-edged giant named after—who else?—Marilyn Bell’s male coach. (Okay, in fairness, he also taught thousands of kids to swim.)

So it was going to take a dramatic turn of events to get me anywhere near the open water—some combination of, oh, a global pandemic that suddenly made people and change rooms scary, plus a stay-at-home order that put nicer lakes out of reach, plus the northern hemisphere’s hottest summer on record, plus a devastating lack of AC in my house. At a spot near Ontario Place on an impossibly humid afternoon, coaxed in by the reassuring presence of couples and children, I couldn’t resist any longer: I waded in to my ankles, then my knees, then my hips. The water was cool and eel-free. I dropped my shoulders under the waves (face: still off limits) and started paddling. I was swimming in the lake.

It’s probably the only time that I—truly incapable of improving on a half-assed breaststroke—have ever had anything in common with elite swimmers. With indoor pools closed by COVID-19, they were forced to do their training in lakes. “After our move to open water, we saw a lot of creativity,” says Bette El-Hawary, the executive director of Swim Nova Scotia. Some coaches climbed into kayaks or onto paddleboards; the athletes would swim to them and back. “Other teams bought rope from Canadian Tire and pool noodles from the dollar store,” El-Hawary says, “to set up the lanes and make their own 50-metre pool.”

(Related: 6 Reasons Swimming is So Good for You)

Swimming Wenting LiImage: Wenting Li

The swimmers liked the novelty of open-water training, but it was an adjustment for them too: Certain lakes had more aquatic life than others, the water might get choppy and visibility could be an issue. “There’s always some fear of the unknown,” El-Hawary says. The training demanded more of the athletes, as well; out in the lake, there’s nothing to rest on. But that’s the challenge of swimming, says Liz Johnson, lead physiologist with the Canadian Sport Institute Pacific. “It’s really unique in the fact that there’s no coasting.”

Even in a lake hovering around 20°C, swimmers working against the drag of the water are going to generate a lot of heat. “Our resting core temperature is 37°C, and I’ve measured swimmers getting above 39.5°C, which is really warm, given the amount of heat lost to the open water,” Johnson says. What she hasn’t measured, though, is a racing heart. That’s because hearts work differently in the water: Since we’re exercising in a more or less horizontal position, our hearts aren’t fighting against gravity to pump blood back to them. “Your heart rate when swimming is generally 10 to 15 beats lower per minute than when you’re doing something of similar intensity on land, like running or cycling,” Johnson says.

(Related: 11 Ways You’ve Been Swimming All Wrong)

So open-water swimming might not feel like your typical workout, and open-water swimmers might not look like your typical athletes, either. It’s one of the few sports where body fat actually offers a competitive advantage, helping with buoyancy and performance. (If you float easily, you don’t have to work as hard to keep afloat.) Female marathon swimmers have comparatively more body fat than male marathon swimmers do—roughly 31 percent to 19, according to a 2014 Swiss study—and the longer the race, the more we excel. Lynne Cox set both the women’s and men’s world records for swimming the English Channel—twice. In fact, in ultra-distance swims, even the average woman is faster than the average man. As Cox writes in her memoir, “Thank God (or Ben & Jerry’s) for my body fat.”

Our bodies are built to do well in the water. But the more I return to the lake, the better my mind does too. It’s the rare place where I can forget about the pandemic: I don’t need to remember a mask or anxiously calculate my distance from the nearest passing person, because there is no one around me. I can focus on the cold water lapping across my warm back as I dog-paddle forward or the extra kick in my legs that lets me travel a little further out. Everything else gets quiet.

El-Hawary has spent more summers than she can count swimming in Halifax’s lakes, but whenever she drops her towel at the boat launch and makes her way in, she finds the water different. “One day, I’m swimming against a headwind. The next day, I’ve got a tailwind. The next, there’s early-morning fog,” she says. “I never have a plan, because the elements change all the time.” It’s another reason open-water swimming is the perfect way to stay cool in a pandemic summer. When each day remains stubbornly indistinguishable from the one before it, the lake still holds the promise of surprise.

Next: The Benefits of Biking, For Your Body and Mind

Originally Published in Best Health Canada