Think exercise sessions must last 20 minutes to 60 minutes to get you fit? Think again.
"This is completely unrealistic for most people," says Glenn A. Gaesser, a professor of exercise physiology at the University of Virginia in Charlottesville, who specializes in jump-starting sedentary adults.
In a departure from what many people mistake for fitness gospel, Gaesser and many of his colleagues now say you can cut exercise sessions down to as little as 10 minutes and still reap gains. You won't drop three dress sizes or realize those six-pack abs--even in fitness, you get what you pay for--but you will feel better and reduce your disease risk. Overall, not a bad deal.
Only about 15% of Americans comply with the American College of Sports Medicine's recommendations for adult fitness, which prescribe 20 minutes to 60 minutes of aerobic exercise, three to five days a week, plus strengthening and flexibility exercises two to three days a week.
"Most people complain that they 'don't have time' " for this much exercise, says Gaesser, who co-chaired the committee that wrote these guidelines in 1998. That same year, taking their cue from accumulating study data on short bouts of exercise, ACSM's experts first offered busy people a way to boost fitness without setting aside huge chunks of time. "In parentheses, almost as an afterthought," Gaesser says, "we stated that a daily workout of at least half an hour could be broken up into 10-minute segments if necessary throughout the day."
Nearly anyone could fit such short bouts of activity into their day, decided Gaesser, who built an exercise program around the theory. Participants in the program would perform 10-minute "sparks" of exercise 15 times each week. These consisted of:
* Seven to 10 "aerobic sparks," such as dancing to music, an early-morning "pick up the paper" walk or a midday office stair climb.
* Two to four "strength training sparks," such as calisthenics or resistance exercises using weights.
* Two to four "flexibility sparks," such as stretching at work or at home.
He combined these 10-minute exercise "sparks" with a sensible eating plan and tested the program on 40 sedentary people. On average, in three weeks, participants lost a respectable three pounds, boosted their aerobic capacity by 10% to 15%, showed strength and muscular endurance increases ranging from 40% to 100%, improved flexibility scores and significantly improved their cholesterol profiles--with reductions of as much as 34 points among those in the high-risk range.
"With relatively small amounts of exercise that people could easily fit into their daily lives, they were able to improve their health, fitness and well-being," says Gaesser.
The idea that short bouts of exercise can yield significant health benefits has been gaining attention in recent years as public health officials try to move sedentary Americans off the couch and reduce epidemic rates of obesity.
This summer, the American Heart Assn. journal Circulation published a study indicating that two 15-minute exercise sessions curb heart disease risk as much as a single 30-minute session. The association stamp marked mainstream acceptance of a concept that was breakthrough thinking 10 years ago, when a report published in the American Journal of Cardiology first suggested that three, 10-minute exercise bouts per day offered fitness benefits similar to those gained from one 30-minute session.
"We know that there's a threshold level of activity needed to gain health benefits," says John M. Jakicic, an assistant professor of psychiatry and human behavior at the Brown University School of Medicine in Providence, R.I., who has done extensive research on intermittent exercise. "But it's not necessary to get all this activity at one time." Beginners, particularly, like the idea of bite-size sessions.
Jakicic's research indicates that new exercisers are more likely to stick with a fitness regimen when it's broken into 10-minute bouts. His 18-month study of 148 sedentary, overweight women--published last year in the Journal of the American Medical Assn.--suggested that short bouts of exercise offered weight loss and fitness benefits comparable to those achieved in longer sessions. Participants who used home exercise equipment such as treadmills were even more likely to adhere. For six months, that is. After that, the rate falls off.
For those already in the exercise habit, switching to shorter workouts may not make sense, except perhaps when holidays or work pressures put the squeeze on workout time. "It's a great temporary stopgap that will help you maintain your fitness until you can get back to your normal routine," Jakicic says. "But the caveat is that the effects are minimized significantly if you're just strolling through the mall window-shopping."
To be most effective, each 10-minute workout must be done at least at a moderate pace, which he defines as "walking with a purpose" or "walking as if you're going to miss your train."