Swimmers competing in the 2016 Ironman World Championship triathlon in Kailua-Kona, Hawaii

© Tom Pennington/Getty Images

Swimmers competing in the 2016 Ironman World Championship triathlon in Kailua-Kona, Hawaii

You don’t have to swim 3.8 kilometres—or follow that up with a 180-kilometre bike ride and then run a marathon, like these Ironman triathlon competitors—to celebrate Swim a Lap Day. But if you can swim, and have a place to swim a lap, today’s the day to do it. And then maybe, just maybe, you’ll get inspired to swim another lap, and another. Who knows, maybe with the right training you’ll end up in a photo like this, chopping your way through the surf in Kailua Bay, on your way to finishing all 226 kilometres of the triathlon.