With summer just around the corner, there are plenty of opportunities for enjoyable activities that also give your body a good workout. But before you reach for a double-dip ice cream cone in anticipation of all the extra calories you'll burn, here's a guide to some popular activities, what they'll do for your body in about 30 minutes -- and roughly how many calories they'll eat up. As you'll see, the real payoff comes from longer periods of activity: a few hours of hiking, walking 18 holes on the golf course, playing volleyball all morning, for example.

Basketball. Whether you shoot hoops on a steamy asphalt court or play in an air-conditioned gym, basketball offers an aerobic, weight-bearing workout that is good for the heart, bones, upper arms and legs. Calories burned per half-hour: about 200 -- roughly equal to a snack-size bag of pretzels.

Biking. Even leisurely cycling helps condition the lower body. Fast-paced biking is aerobic, giving the heart a workout, too. Calories burned: about 225 -- about what you find in a small order of McDonald's fries.

Body surfing. Swimming to catch the waves can be aerobic -- good for heart, lungs and blood vessels -- as well as arms and legs. Calories burned: about 100 -- roughly three-fourths of that found in a 12-ounce can of regular soda pop.

Calisthenics. Push-ups, ab crunches, leg lifts and lunges help tone and strengthen various muscles. Calories burned: 125 -- roughly one honey-barbecued KFC chicken wing.

Canoeing. Paddling is great for the upper arms and chest. Whitewater workouts can also be aerobic, but just moseying down the creek will burn about 120 calories -- about a small soft ice cream cone.

Gardening. Work the yard to work the upper body. Raking and sweeping helps strengthen core muscles (from upper thighs to abs). Calories burned per half-hour: about 150 -- or about the amount in a three-ounce crab cake.

Golf. Walk the links -- if the course allows -- to strengthen the lower body from legs to abs. Driving and chipping is good for the upper body. Even putting and miniature golf are load-bearing activities that help preserve bone. Calories burned: 120 for miniature golf; 180 for golf, or about what you'll get in two bottles of ultra-light beer.

Hiking. Not only can you enjoy nature, but this load-bearing activity is also a bone-preserver. Light hiking burns about 225 calories. Add a 10-pound backpack and you'll burn about 275 -- about equal to a slice of pepperoni pizza.

In-line skating. Gliding along the pavement at about 8 mph gives a great workout to the lower body and burns about 190 calories -- roughly a margarita.

Sailing. Staying upright in a moving sailboat helps balance and gives your muscles an isometric workout, but unless you're doing competitive racing, it burns only about 115 calories--or about an ear of corn on the cob with a little butter.

Softball/baseball. Playing catch is great for the arms; hitting and fielding can work the legs, arms and cardiovascular system, although baseball isn't a true aerobic sport. Baseball/softball burns about 200 calories -- about four medium chocolate chip cookies.

Tennis. Good for overall conditioning and burning calories (especially singles), tennis also helps preserve bone. Figure 210 calories -- about the amount found in four cups of popcorn (popped with oil) or about two-thirds of a kid-size movie theater serving of popcorn.

Walking. It strengthens abs, builds bone, conditions the lower body and can provide an aerobic workout, depending on pace. Strolling (2.5 mph) burns about 100 calories; brisk walking (4.5 mph) burns double that, or about the amount found in a small milkshake.

Volleyball. Play it on the beach, in the back yard or the Mall for a fun activity that works the upper arms and legs, and counts as a load-bearing exercise that's good for bones. Burns about 100 calories -- roughly that found in a junior Frosty at Wendy's.

-- Sally Squires

Share Your Tips or ask questions about healthy nutrition and activity when Sally Squires hosts the Lean Plate Club online chat, from 1 to 2 p.m. today, on www.washingtonpost.com. New To The Club? The Lean Plate Club is devoted to healthy eating and boosting activity. To learn more, and subscribe to our free e-newsletter, visit www.washingtonpost.com/leanplateclub.