Ask the Doctors

Dear Doctor: My New Year's resolution was to get more exercise and, I hope, lose a few pounds. Walking is an activity I know I can stick with, but I keep hearing that I should aim for 10,000 steps a day. Where does that number come from, and am I wasting my time if I do less?

Dear Reader: In the battle to sit less and move more, you've already nailed the crucial element -- picking an activity that will survive the inevitable day that your New Year's fervor wears off. Walking is a great option -- it's easy, inexpensive and low-impact, and can be done just about anywhere. Best of all, walking has multiple health benefits.

Walking will do more than just help you control your weight. In fact, even if you don't lose any weight at all, you'll still come out ahead. People who are physically active lower their risk of stroke, heart disease, type 2 diabetes, depression and even some cancers. Bottom line -- they live longer.

For optimal health benefits, the Centers for Disease Control and Prevention say we should spend at least 150 minutes per week doing a moderately paced aerobic activity for no less than 10 minutes at a stretch. (Or 75 minutes per week of vigorous physical activity, but that's an answer to a different question.)

Those 150 minutes of moderate activity can absolutely be spent in your chosen method -- walking -- as long as it's at a brisk pace. Three to four miles per hour is about right for most of us. That's fast enough so that your heart gets pumping, yet you're still able to carry on a conversation. Which brings us to the question of distance, and the mystery of the 10,000 steps.

It turns out that this goal dates back to the mid-1960s, when a pedometer sold in Japan was marketed as "manpo-kei," which translates to "10,000 steps meter." More than 50 years later, we're still in thrall to that clever bit of advertising.

But those 10,000 steps -- that's about five miles -- had a toehold in science. A study at the time found that men who burned 2,000 calories per week through exercise measurably lowered their risk of heart disease. Since a five-mile walk uses roughly 300 calories, to burn 2,000 calories per week takes 10,000 steps.

Is 10,000 steps a make-or-break number from the outset? The short answer is no. Any amount of physical activity above and beyond what you're presently doing is beneficial. The main thing is to ease into your new exercise program in a way that's both safe and sustainable.

Begin with a comfortable pace and a reasonable distance. Maybe that's a 10-minute walk around the block or a brisk two miles to work. Challenge yourself to go a bit farther each week. Whether you're taken with the symmetry of 10,000 steps, or prefer the CDC's recommendation of 150 minutes of exercise per week, what matters most is that you get -- and stay -- moving.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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