NEW YORK — The procrastinators, the super-busy, and the easily bored in pursuit of a manageable fitness routine may find what they seek in the 10-minute workout.
Experts say what these short bursts of activity, sometimes called exercise snacking, lack in duration they can make up for in intensity.
"You can get a good enough workout that can make real metabolic changes to your body," said Liz Neporent, co-author of "The Thin in 10 Weight-Loss Plan" along with fitness instructor Jessica Smith.
"It can help you lose weight, reduce stress and basically give you all the benefits that we know come from exercise."
The American College of Sports Medicine (ACSM) recommends that most adults to engage in at least 150 minutes of moderate-intensity exercise each week.
But multiple shorter sessions of at least 10 minutes are acceptable and even people unable to meet the minimums still benefit from some activity, according to ACSM.
Neporent, who writes on health and fitness, said mainstream science is finding that if you increase intensity you can decrease time.
That approach can work for a lot of people, she said, because poll after poll has shown that the number one objection to not getting a workout in is time.
"The typical recommendation is to do 30 minutes, so if we told you that you could do 10 minutes at a time, you might actually have a better shot at getting it done," she said.
To make the most of 10 minutes, Neporent and Smith favor a hybrid of cardio and strength exercises.
"You want to get in something that's heart-healthy, and something that's good for your muscles and bones," Neporent said. "A lot of our workouts (in the book) tend to be circuit-weighted to maximize time."
They also promote the 10-minute walk; the meal plan section extends the theme with recipes that take 10 minutes or less to prepare.
Amy Dixon, creator of the "Give Me 10" DVD series of 10-minute workouts, said studies show shorter, but more consistent, workouts can yield dramatic results.
"If I had 10 minutes I would do fairly intense strength training, total body workouts with dumbbells or kettle bells interspersed with cardio intervals like jumping jacks," said Dixon, who is Group Fitness Manager at an Equinox fitness center in Santa Monica, Calif.
She's seen too many people spend 60 minutes just going through the motions of a cardiovascular workout.
"If you're reading a magazine," she said, "you're not working out."
Dr. Carl Foster, a professor in the exercise and sports science department at the University of Wisconsin-La Crosse, said there are unique advantages to high-intensity training for the young and the fit.
"There are things you gain that you can't get from low-intensity workouts because you're using muscle fibers that are sedentary in a walk," he said.
For the middle-aged or older, high-intensity exercise has its perils.
"Somewhere around age 45 for men and 55 for women, you worry about the dark side of exercise," he said.
"Studies are clear that when people have catastrophes, such as heart attacks, they are almost always related to inappropriately high-intensity exercise."
Sometimes high-intensity routines are just too uncomfortable to be habit-forming, he said.
"Yes it can be done. You can do the work in 10 minutes but then it takes you 40 minutes to recover."
Foster predicts the focus on high-intensity interval training will wane.
"It will be like seasoning in food: you want to feel like an athlete, so let's do some of it in the middle of the workout," he said.
Before you leap into high-intensity training, he urges, be sure to have at least six months of normal training behind you. Then gradually add five or 10 seconds that are a little harder.
The biggest risk is that people who've been sedentary will suddenly decide to get in shape with high-intensity training.
"For middle-aged and older people, high-intensity training can be a trap that leads to health problems," Foster said.
"The people who are moderately active on a routine basis are the people who don't get heart attacks."