Ever since my eighth grade gym teacher taught us that aerobic exercise, aka cardio, doesn’t count unless you put in at least 20 minutes, I’ve been religious about keeping my workouts at least 30 minutes long. (It doesn’t feel worth it to change into full on running gear for just 15 minutes, amiright?) During the week, I alternate between one hour runs and 45 minute conditioning/plyometrics sessions; and on weekends, I might take a 90 minute yoga class. But because of such workout habits, I give up on working out at all when I can’t carve out an hour and a half before dinner. But a new study on the effects of mini workouts (bursts of aerobic activity) shows that when it comes to weight loss, it’s the intensity, not the consecutive minutes, that count. In other words, every minute of your exercise counts cumulatively, whether you do it in one hard core session or little bursts.
To find out if intensity or duration matters more for body weight, researchers at the University of Utah compiled the daily activity levels of 2,202 women and 2,309 men. The researchers defined moderate-to-vigorous activity as 2,020 Counts per Minute as determined by the accelerometer (roughly equivalent to walking at 3.0 mph). Then they divided the activities to higher-intensity bouts (>2,020 CPM for 10 minutes or longer), higher-intensity short bouts (>2,020 CPM for less than 10 minutes), lower-intensity long bouts (< 2,019 CPM for 10 minutes or longer), and lower-intensity short bouts (<2,019 CPM for 10 minutes or longer).
They found that intensity was a greater factor in BMI than the duration, which isn’t surprising since the intensity level chosen here was fairly low to begin with. But what’s really astonishing is how much just one minute of activity affects a person’s BMI. For women, each daily minute spent in higher-intensity short bouts was equivalent of 0.7 decrease in BMI, or 0.41 lbs in weight. That means adding just one more minute of exercise each day will make you weigh 1/2 lb less! Each daily minute of higher-intensity activity also lowered the chance of obesity by astonishing 5% for women, and 2% for men.
What this means: “higher-intensity” as defined here really was close to what you might think of as moderate activity, so the great news is that you don’t have to try anything crazy hard (like the Tabatha method, for instance) to reap the benefits. Even one minute of exercise will count toward healthy weight, whether or not it’s consecutive. So walk to your mailbox, walk your dog, take the stairs, do some gardening, or even do a quick 5 minute jump rope session before getting ready for work! That’s what I’ll be trying out, next time I don’t have time for a long run.
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