You've probably heard the advice: Get 30 minutes of aerobic exercise at least 5 days a week. But does a one-size-fits-all prescription really make sense?
That dictum comes from the Centers for Disease Control and Prevention—and it's backed by plenty of studies, explains Lisa Cadmus-Bertram, PhD, assistant professor of kinesiology at University of Wisconsin-Madison. But the American College of Sports Medicine—a respected research group—refines the advice to say that if you go hard, your aerobic exercise can be just 75 minutes a week. Of course, the ACSM experts also expect you to add strength training 2 to 3 days a week, and stretch on at least 2 days out of every week.
So what's the right amount for you?
It really depends on what you're looking for, says Cadmus-Bertram. First, not everyone responds the same to every exercise: Some people are more suited to cardio, while others find it easier to crank out push-ups by the dozen, she explains. And secondly, the most efficient exercise prescription depends on what your workout goals are. A marathoner's training schedule looks quite different than a yoga teacher in training.
Here are some tips to help you determine what exercise schedule is best for you.
If you want to lose weight...
The good news is you don't need to spend half your day in the gym to lose weight, but you do need to pay attention to diet (no surprise!). Aim for 300 minutes of moderate or vigorous physical activity each week, Cadmus-Bertram says, which a recent study published in JAMA Oncology found was linked to the greatest weight and body-fat loss.
While it's certainly possible to lose weight doing fewer than 300 minutes of exercise a week, the bottom line is you need to burn more calories than you take in to lose weight, she explains. "And for most people, there is more room to cut calorie intake than expend very large numbers of additional calories."
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And be sure to incorporate resistance training in addition to cardio, she adds. Strength training helps you build muscle mass, which ramps up your basal metabolic rate, meaning you'll burn more calories even when your body is resting. Also consider rotating between a variety of exercises, throwing in new ones to keep challenging your body, she says.
If you want to tone up...
Add strength and resistance training, and keep your cardio at the 150-minutes-per-week mark (or 75 minutes, if you up the intensity). Muscle tone depends not only on the muscles, but also on the amount of fat on top of them, Cadmus-Bertram explains. Crunches might get you six-pack abs, but for most normal-weight people, the muscles will not be visible unless body fat levels are quite low, she says.
Start by adding resistance training 2 to 3 days a week, Cadmus-Bertram recommends. When you're ready to up the intensity, add another day of strength training, focusing on each major muscle group twice a week, according to recommendations from the American College of Sports Medicine.
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If you want to live longer...
Be active and stay active, Cadmus-Bertram says. Get the recommended 150 minutes of moderate-intensity activity per week (or 75-minutes of vigorous-intensity activity), plus strength or resistance training twice a week. Make sure to include stretching, which will make staying active easier and potentially protect against injury.
This target helps you strengthen your heart and lungs, prevent the development of insulin resistance, maintain a healthy weight, and avoid chronic inflammation, explains Cadmus-Bertram.