You go for long walks virtually every day and wear a pedometer to count the steps you take. Most days, you take the 10,000 steps the federal Centers for Disease Control and Prevention says is necessary for an "active" lifestyle. You think you get enough exercise.
You're chained to your desk at the office during the day. But most nights you hit the gym, lifting weights and doing cardio. And most weekends, you play golf or tennis or other active sports. You think you get enough exercise.
Think again, says the American College of Sports Medicine, the professional association of personal trainers and other exercise professionals.
ACSM recently published new guidelines in its journal, Medicine & Science in Sports Exercise, about how much of what kinds of exercise is "enough."
The heavily footnoted journal article refers to dozens of studies that indicate how much exercise is needed to produce significant health benefits. For instance, the recommendations concerning cardio-respiratory fitness are based in large part on the amount of exercise a study indicated can lower mortality rates by 60 percent compared to sedentary people.
"Pedometers are popular and effective for promoting physical activity and modest weight loss," the ACSM acknowledged in the guidelines, "but they provide an inexact index of exercise volume. They are limited in that the 'quality' (e.g., speed, grade, duration) of steps often cannot be determined."
And no matter how long or how briskly you walk, walking alone cannot meet all your fitness needs, according to the ACSM.
Health risks incurred by spending hours sitting at a desk or in front of the television can't be offset with daily visits to the gym, no matter how hard you work out.
"Sedentariness is detrimental even among individuals who meet current physical activity recommendations," the ACSM says. "The evidence suggests it is not enough to consider whether an individual engages in adequate physical activity to attain health benefits, but also that health and fitness professionals should be concerned about the amount of time clients spend in activities such as television watching and sitting at a desk."
To reduce the harm that can be done by prolonged periods of sitting, get up from your desk every hour or so, stretch and take a short walk around the office. If there's no time for that, just stand up for a minute or two. When you're watching TV at home, get up and stretch during the commercials, and take a short walk around the house.
Ron DeAngelo, director of sports-performance training at the University of Pittsburgh Medical Center's Center for Sports Medicine, called the new guidelines a "wake-up call" for some people. "A lot of times people think they are accomplishing a lot more than they really are."