Is it possible to drop pounds as you prune your trees? To whittle your waist while weeding your lawn?

Yes, says Bunny Guinness, a British garden designer and co-author of "Garden Your Way to Health and Fitness."

Guinness estimates that one hour of mowing, pruning or shoveling burns as many calories as jogging four miles. She says you can spend an hour in the gym or three hours weeding and get the same results: 600 to 700 calories burned. And, she notes, since gardening requires sustained activity, you actually burn more fats than carbohydrates when you garden. Burning fat is good for weight loss.

She advises you to alternate arms while raking, shoveling or doing other back-and-forth motions. It will feel weird at first, but it is better for your body to stretch the muscles equally on both sides.