Stand-up paddleboarding (called SUP for short) was invented in Hawaii by surfers looking for a way to keep up their training on days with disappointing waves.
Over the past decade, it's won over a much wider following as word has spread that a wide, stable board and a paddle make it possible to traverse long distances while getting one heck of a core workout.
Plus, unlike surfing, practically anybody can do it.
"Racing is starting to explode. Everybody wants to train for distance," says Kathy Summers, founder of Stand Up Paddle DC, who got into SUP for a popular reason: injury. After busting her ankle in 2009, the California native realized running wasn't in the cards. But SUP, which she'd tried in Hermosa Beach, reminded her of the balance exercises she was performing in physical therapy.
Summers found she couldn't go for a ride without people yelling questions at her from the Key Bridge, and she quickly recognized a business opportunity. Instead of simply renting SUP equipment, Summers offers small-group lessons in technique and fitness classes.
"If you can stand and walk, you can do it," she says. So the fun comes from challenging yourself and exploring the versatility of the boards. There's standard paddling for speed and distance, which is a popular cross-training option for runners and cyclists. You can also use the wobbly surface for yoga poses or moves you'd expect to see at a gym -- burpees, squats, mountain climbers, etc.
Next season, she's planning to add a PaddleFit boot camp, based on the rapidly growing exercise system devised by Brody Welte. The fitness instructor's first SUP ride in Hawaii in 2007 left him exhausted but exhilarated.
"And it just clicked," says Welte, who's developed programming for the boards in the water, on land and even indoors. You can buy SUP ergometers (imagine a rowing machine you stand on) and paddle attachments for rowing machines to mimic the stroke.