It's easy to scoff at the idea of gardening as exercise -- until you've actually grabbed a trowel and dug in. More and more, scientists are confirming what avid gardeners have known all along: Wrestling with stubborn weeds, trimming hedges, and spreading mulch are all good ways to work up a very respectable, healthy sweat. Doing work around the garden also tends to be more mentally and emotionally rewarding than trudging away on the treadmill at the gym.
"Gardening is a great way to maintain flexibility and tone muscles," says Melissa Roti, an assistant professor in the department of movement science, sport, and leisure studies at Westfield State College in Westfield, Massachusetts. Bending to pick flowers or reaching to prune a vine, for example, can help you stay limber. Digging, hoeing, and lifting build core body strength, which protects against back problems and helps prevent falls.
The more you exert yourself, the greater the benefits. "Household and yard activities increase metabolic rate threefold to fivefold," says Steven Blair, a professor of exercise science at the University of South Carolina and coauthor of "Active Living Every Day" (Human Kinetics Publishers; 2001). That's enough to reduce blood pressure and improve cholesterol levels when a gardener works for at least 30 minutes five days a week. Tasks that are strenuous enough to leave a gardener feeling slightly winded -- pushing a hand mower or raking, for example -- will improve cardiovascular fitness. Gardening, like more traditional forms of exercise, has been shown to lower the risk of heart disease and help ward off type 2 (adult-onset) diabetes.
Calorically speaking, an afternoon of raking, trimming, and weeding rates as high as more serious workouts. On average, gardening burns about 265 calories an hour, more than expended by brisk walking. In a study of 4,576 women, researchers at Utrecht University in the Netherlands found that those who gardened tended to weigh less and have slimmer waistlines than subjects without a horticultural bent.
Less strenuous forms of yard work have pluses, too. They are appropriate for people with arthritis and can actually ease their pain, says Joy Harrison, executive director of the American Horticultural Therapy Association.
The benefits of being active in the garden go beyond physical health. Studies show that almost any kind of moderate exercise reduces stress. But gardening may have an added advantage. "Instead of blowing your top at your boss, you can attack those weeds to release your aggressions -- and have a beautiful garden to enjoy when you're done," says Roti, who grows and tends to perennials. Another bonus: A good workout in the yard may help you get a better night's sleep.
Simply enjoying a patch of green, even from afar, can be therapeutic. When Texas A&M University researcher Roger Ulrich compared hospital records of patients recovering from gallbladder surgery, he discovered that the ones whose rooms had a view of nature recovered more quickly than those who looked out at a brick wall.
Ultimately, what may be best about flexing a green thumb is that it's such a pleasure it hardly feels like exercise. "When the first good weather arrives, the biggest problem we see is people overdoing it," says Sandra Mason, a horticulture educator at the University of Illinois Extension in Champaign County. "Once people get started, they don't want to stop."
Perennial Safety Advice
Some pointers on lessening the risk of strain or injury in the garden.
Carry with Care
According to Britain's Royal Society for the Prevention of Accidents, flowerpots are the second most dangerous object in the garden (lawn mowers top the list). The reason: Lifting heavy pots can cause sprains and strains. Whenever you hoist or haul, bend your knees and keep heavy objects close to your body to avoid straining back muscles. Don't overload wheelbarrows or weed bags. When you're done for the day, prevent soreness by taking a few minutes to stretch.
Get a Shot
Be sure your tetanus vaccination is up to date (experts recommend getting one every 10 years). According to the Centers for Disease Control and Prevention, 31 percent of tetanus-related injuries occur in yards and gardens or on farms. The bacterium that causes the disease resides in the soil and can enter through cuts in the skin, putting gardeners at particular risk.
Dress for the Task
Wear gardening gloves, long-sleeve shirts, and pants to protect skin from branches, thorns, insects, and sunlight. If you're going to be in the sun, wear a wide-brimmed hat and use a broad-spectrum sunscreen (SPF 15 or higher). Hydrate frequently, particularly on hot days. Wear goggles when working with chemicals or when using tools that generate flying debris. If you're going to kneel for a while, wear knee pads or use a foam mat.
Choose the Right Tools
Look for lightweight tools that let you get a good, strong grip. For small tools, this may mean seeking out long handles that can accommodate all of your fingers. Buy for comfort, but don't necessarily rely on labels such as "ergonomic." In a 2004 study, Julie Jepsen Thomas, head of the department of occupational therapy at the University of Toledo, in Ohio, compared standard trowels with those marketed as ergonomic. Instruments that measure wrist movement detected no difference, and volunteers who tested both tools reported that their ease and comfort during use were about the same.
Calories Burned Per Hour
How various gardening tasks stack up against more traditional forms of exercise (calculated for a 135-pound individual):
215 Walking (leisure)
230 Brisk walking
245 Moderate swimming/water aerobics
275 Trimming shrubs by hand
305 Digging, spading
370 Mowing the lawn (push mower)