Surprise risk: This water sport, which originated in Hawaii but is now catching on across the U.S., requires a surfer's balance and a Venetian gondolier's sense of timing. You stand on a floating board that's more stable than a surfboard and use a long paddle to propel yourself. Biceps of steel aren't necessary, but strong, flexible feet are, because that's what you use to turn and stabilize the board and your body. Many first-timers are shocked by how much their foot muscles burn after a few miles of steady paddling, says Jessica Matthews, an exercise physiologist for the American Council on Exercise (ACE).
Ouch! Factor (Scale is 1 to 5, where 5 is maximum pain potential): 4 while leaning hard to one side to race an incoming storm; 2 while sitting on the beach the next day.
Paddle safely: Before hitting the water, stretch by your feet by rolling your ankles and pointing and flexing your toes. While paddling, keep your knees and ankles soft and flexible, Matthews says. Also try to root all four corners of your feet into the board, distributing your weight equally—even when you get tired and want to roll your ankles inward.