Ask the doctors: Increasing exercise – even in small ways – is necessary

Dear Doctor: My kids say you’re not supposed to admit it, but I hate to exercise. Running a mile once or twice a week is really the most I can manage. Should I even bother?

Dear Reader: In a word, yes. While it would be great if you enjoyed exercising enough to do more of it more often, intriguing new research suggests that when it comes to physical activity, every little bit helps. In fact, a study conducted on mice at the University of Texas Southwestern Medical Center in Dallas found that just one workout kept the nerve cells in the brain that play a role in metabolism activated for up to two days. The takeaway of that research, which was published in December, is that these neurons respond to even a small amount of activity.

The study focused on two types of neurons, which are part of a brain circuit found in humans as well as in mice. These two neuron types, when activated, have very different jobs. One plays a role in lowering glucose levels, muting appetite and revving up the metabolism. The other neuron type does pretty much the opposite – it ramps up appetite and puts the brakes on metabolism.

Researchers found that a single vigorous workout amplified the activity of the first neuron type – that’s the one that reduces appetite, lowers glucose and causes energy output to increase – for up to two days. At the same time, it suppressed the effects of the second neuron type – the one associated with an increase in hunger and a downshift in metabolic rate – for the same amount of time. While this is good news for people like you who prefer a more modest exercise schedule, the study also contained an incentive to be even more active: It turns out that these changes to neural activity lasted even longer in people who exercised more often.

Speaking of frequency, would you be willing to take on just 10 to 15 minutes of exercise per day? Although exercise classes and gym sessions are typically measured in hours, emerging research is showing that short bouts of exercise – as long as they are done daily – can yield rewards. A study conducted at Pennington Biomedical Research Center in Louisiana found that sedentary women who walked briskly for just 72 minutes per week – that’s about 10 minutes each day – had similar improvement to heart strength and general fitness as did the group that walked almost twice as long.

Another study found that as long as it included at least 60 seconds of high-intensity exercise, a 10-minute workout yielded similar benefits to 45 minutes of steady jogging. And for those who take the long view, numerous studies have associated regular exercise with a lower risk of early death.

When it comes to building on your current level of activity, are there any sports or games you enjoyed in the past and would consider doing again? It doesn’t have to be the same thing every day. Even a 10-minute game of tag with your kids a few times a week will get you moving. Think creatively, and we’re sure you’ll land on a solution. And in the meantime, please do keep running.