Research proves it: the human body is designed for strenuous, long-haul adventure. Recent studies have even suggested that endurance running actually shaped the evolution of the human body. According to Harvard paleoanthropologist Daniel Lieberman, an author of many such studies and The Story of the Human Body, human beings "are fundamentally adapted to get exercise." But the gym is not enough. "There's nothing like the real thing," says Adam Chase, president of the All American Trail Running Association. The outdoors is simply more demanding. "When you're out on the trail, you have to dance through the rocks and routes." That translates into automatic interval training, which strengthens your heart by forcing it to learn to adapt to just about anything. Here's your guide to getting your heart in shape – and having fun while you're at it.
Kayaking: Sports to Make a Strong Heart
Kayaking is that rare upper-body-centric cardio exercise. One of the benefits of aerobic work is that it increases the number of capillaries in the muscles worked; paddling shares this perk with your chest, back, shoulders, and arms, and the natural resistance of the water means that you can't just coast along and expect to remain in motion.
Your lats and shoulders are in constant motion, and your legs, while not doing a lot of weight-bearing movement, play a role in stabilizing you.
Amp It Up
Credit: Steve Glass / Getty Images
Felix Apfaltrer, president of the New York Kayak Polo Club, suggests sprinting out 25 meters on still water in a light, maneuverable kayak, turning, and then sprinting back to where you began. Rest 30 seconds, then repeat the sprint. Do five complete up-and-back laps, adding 10 seconds to each of the rest periods as you go.