Is Five Minutes Of Exercise Really Enough?

Is five minutes a day really enough exercise - or does it just make for a snappy headline?

By Adam Campbell

Earlier this week, the New York Times reported that "Running 5 Minutes a Day Has Long-Lasting Benefits."

Since then, a frenzy of news reports have suggested that perhaps five minutes of exercise a day is all you need.

But is that actually true?

The New York Times story was based on a new study—published in the Journal of the American College of Cardiology—that analysed the association of running and risk of death in more than 55,000 adults over 15 years.

During that period, the scientists found that people who ran weekly had a 45 per cent decreased risk for dying of heart disease—and a 30 per cent decreased risk of death from any cause—than those who didn't run.

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For perspective, during that 15-year period, 3,413 participants died of all causes. Of the runners, 4.3 per cent died, compared to 6.8 per cent of the non-runners. And from heart disease specifically, 1.3 per cent of the runners died compared to 2.6 per cent of the non-runners.

Those numbers might not sound as dramatic as you might have thought, but they are statistically significant. That means the probability that they could have occurred simply by chance is tiny.

Here's where it gets surprising: the amount a person ran didn't seem to matter.

From the New York Times story:

Hence the headline. But there's a catch that the New York Times doesn't tell you about. Turns out, the researchers don't know if the people were actually running as little as 5 to 10 minutes a day. What they do know is that the group who ran the least was accumulating less than 51 minutes of running time per week. It could have been 50 minutes one day a week, or a 15-minute jog on Wednesday, and a 35-minute run on the weekend. Or any combination you can conjure.

I asked Dr Timothy Church, coauthor of the study and a professor at Pennington Biomedical Research Center at Louisiana State University, to better explain the findings to me.

"Realistically, most people aren't going out for 5-minute runs," says Dr Church. "But what these findings show is that there is a benefit to running less than 51 minutes a week, and it may not matter how you accumulate that time. That's not necessarily what we should be striving for, though."

If you're looking to get the most health benefits from exercise, the physical activity guidelines for Australians are a good start.

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"These guidelines are very well written," says Dr. Church, who was a member of the expert committee that created a similar version for Americans. "They're based on thousands of studies, and recommend at least 150 minutes per week of low-intensity level of activity, like walking, for optimal health benefits."

But, he points out, as your intensity—or effort level—rises, the guidelines say you can exercise for less time to achieve those same benefits. "That's why they recommend just 75 minutes per week if your activity is running, instead of walking," says Dr. Church.

What about 5 minutes a day? "We believe that any activity is better than no activity," says Dr. Church. "So if 5 minutes is your starting point, that's great. But you want to try to increase your activity level over time."

Your activity doesn't have to be just running. In fact, Dr Church says he would fall into the "less than 51 minutes of running per week" category. That's because he spends a lot more than 51 minutes a week practicing Brazilian jiu jitsu. And exercise doesn't get any more intense than that.

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