Walking with Nordic poles — rubber-tipped metal rods (shown) that resemble cross-country ski poles — burns extra calories and gives you an upper-body workout while taking stress off the ankles and knees, says PBS's Mark Fenton, who is a fan of Nordic walking. "Using the poles is a great way to intensify your workout," he says. And how: A recent study found that Nordic walkers burn an average of 20 percent more calories and get their heart rates up about five to eight beats per minute higher than regular walkers going at the same speed.

Nordic-walking poles were introduced in the United States in January 2004. They debuted in Finland in 1997, and now about 10 percent of Finns walk with them (go to www.nordicwalking.com for more information).

If you're self-conscious, recruit friends to Nordic-walk with you, or use the poles on wooded trails, where you'll feel less conspicuous.