By getting gamers up on their two feet, Nintendo's Wii workouts are a healthier take on video games than anything that came before (and the cost of the console is dropping). My generation was the first to grow up glued to game graphics, and some of us have the spines to prove it. In medical journals these days, early case reports of "Wii knee" and other orthopedic traumas have been fast followed by serious efforts to understand just how much our bodies stand to gain from Wii workouts. It is already known, as colleague Katherine Hobson reported last year, that in a dual between real and virtual sports, virtual doesn't cut it. But how about basic fitness? Can the Wii give you your daily dose of physical activity? Yes—and no. As it turns out, the Wii offers the real deal for some and little more than virtual exercise for others.
Motohiko Miyachi, a scientist employed by Japan's National Institute of Health and Nutrition, unveiled the latest and most definitive Wii research at the American Heart Association's scientific conference this week. The study was funded by Nintendo, which will use the data in game updates. The report conveniently went public just as the company releases the new edition of its hit exercise program, Wii Fit Plus. Other scientists who have tried to calculate how much energy people burned while playing Wii games didn't use ideal techniques, says Miyachi. Scientists have to measure the oxygen and carbon dioxide players exhale to calculate the energy being burned. That means tying players to cumbersome gas masks, which can limit movement and the degree to which players get into the game.
Instead, Miyachi put players inside a metabolic chamber—a sealed room that lets researchers precisely monitor the gases in the air. It's the Cadillac of exercise physiology tests and something most scientists can't get their hands on. It's also the best way to counter reports like the one in the respected journal BMJ two years ago that used masks and concluded that typical Wii gamers would burn only about 2 percent more calories than people playing with traditional sofabound consoles.
Miyachi's study team had 12 gamers perform each of 68 different activities included in Wii Sports, where players mimic sports like boxing and bowling, and Wii Fit Plus inside the metabolic chamber. The researchers determined the players' METs, or metabolic equivalents. (A MET of 1 is your resting metabolic rate—how much energy you burn in one minute while sitting in a chair. Expending twice as much energy equals 2 METs.) In the metabolic chamber, a third of the 68 activities got into a MET range of 3 to 6, considered moderate intensity. Thirty minutes of moderate-intensity exercise five days a week satisfies the AHA's minimal-activity recommendations for adults. The "single arm stand"—repeatedly lying down, raising the upper body, and using one arm to push up to a standing position—burned the most energy, 5.6 METs. But most workouts involve a mix of activities, so the average matters more. METs for Wii Fit yoga and balance moves were in the 2s, on average; Wii Fit resistance and aerobics were in the 3s; and WiiSports' average was 3. That's borderline moderate.
Miyachi says the moderate exercises in these two Wii games can satisfy some of your basic requirements, but I'd like you to know a little more about METs before you fill up your free time with Wii time. Most healthy people need to burn more than 700 calories a week in vigorous exercise, and exercise physiologists have taken the time to calculate the METs for a variety of activities to help you get there. Since 1 MET is roughly 1 calorie, you can multiply the minutes you spend jogging, say, by the 10-MET rating for that exercise to estimate the calories burned. You don't even have to do the math. Just be aware you need to get at least 500 to 1,000 METs a week with moderate or harder exercise. While staying in the 3-to-6-MET zone will burn some calories, which could help you maintain your weight, most young people won't be training at a high enough level to improve cardiovascular function.
Here's some perspective: A doctor may limit a patient's activities to 5 METs or less after he or she has a heart attack. Even sex (3 to 4 METs for an average middle-aged couple, with climax at 4 to 5 METs) may be off the table. So the average Wii workout is just what the doctor ordered—for a cardiac patient. Furthermore, METs of 3 to 6 are considered moderate for a typical middle-aged individual. Moderate for someone age 20 to 39 is more like 5 to 7 METs. If you're over 65, on the other hand, the Wii can offer you a solid workout; for you, moderate activity is around 3 to 5 METs. People over 80, for whom moderate is about 2 to 3 METs, will really be sweating.
Since the Wii health payoff rises with age, the game machine has a bright future in rehabilitation settings. Mershon Hinkel, a Philadelphia-based occupational therapist who is so jazzed by the Wii's rehab potential that she's known as "the Wii OT," teaches other therapists to integrate Wii workouts into rehab. Besides helping encourage her frail patients to stand up and move about, says Hinkel, the virtual worlds are sometimes "magical" to her patients, who forget for a while about their aches and pains. A virtual bowling league known as the Penswick Panthers has popped up at the retirement community she serves. "One gentleman in particular, he had a stroke, and he's one of the top bowlers," says Hinkel. "He couldn't do that at the bowling alley." Even picking on-screen avatars prompts old memories, with patients seeing their former selves in the little animated characters. "Reminiscing is very good for the older crowd," she says. "They relive their youth in that moment."
Wii rehab is wonderful for helping people take baby steps forward after injuries or circumvent disabilities that aren't going away. As a physical rehabilitation physician, I want to see people attain their highest level of function—that's what my day job is all about. That's why I'd be sad to see the kind of people who aren't my patients use the Wii as an excuse for not doing the real thing. For healthy folks under 40, whose workout time is precious, the Wii is a step back. Train hard at a real gym. Do things you'll reminisce about. And please, bowl with a ball.