When 8 Minutes Is Not Enough continued...
For instance, he says, if you want to improve your physical performance - say, increase your speed in a 10K race or win a power-lifting contest - working out for a few minutes a day probably won't do you much good.
If you're interested in improving a specific aspect of your fitness, such as strength, endurance, or flexibility, quick workouts might help. But, he says, that's only if it comes on top of any exercise routine you're already following.
"If the eight minutes of exercise is in addition to what you're already doing, excess calories will be burned, and - assuming your caloric intake doesn't change - this deficit will result in better weight management," he tells WebMD.
Hill adds that only so many calories can be burned in eight minutes, regardless of the intensity or the type of activity. Assuming you burn about 100 calories in each daily eight-minute session, burning a pound of fat (3,500 calories) would take you 35 days.
Even among fitness trainers, there's considerable doubt that eight minutes of exercise a day is really enough for anyone.
"Eight minutes a day, of course, is better than nothing, but the surgeon general and the American College of Sports Medicine are still recommending 20 to 60 minutes of cardiovascular exercise three to five times a week, and strength training two to three times a week on alternating days," says fitness specialist Kelli Calabrese, MS, ACE, CSCS.
The benefits of quick workouts, says certified fitness trainer Leigh Crews, are that they simplify a subject many people find confusing; provide step-by-step guidelines to follow; recommend a reduced caloric intake; and set up an easy-to-follow schedule.
"You're not really meeting the guidelines set forth by the ACSM, but if you're a totally sedentary individual, even training each muscle group once a week is going to show results over no training at all," says Crews, who specializes in continuing education for fitness professionals.