A: Having your feet hit the ground for 30 minutes every day is as important as making sure your car has tires. So, sure, videos that get you on your feet for 30 minutes are as good as walking. But don't wait until you get a video. Walking around your dining room table or chasing your spouse around the bedroom is effective too!
Q: In your books and columns, you are firm about getting 30 minutes of walking every day, which works out to 210 minutes a week. When I'm super busy, can I stagger days or cut back to 10 minutes, as long as I average 210 minutes a week?
A: Walking turns on genes that apparently require daily activity to stay on. Normally, we hate to give you absolutes when the data aren't perfectly clear—but this case is an exception. We believe that 30 minutes a day is necessary. However, when you're super busy (or just in the mood for quick, short walks), you can break up the time and walk in intervals as small as 10 minutes. Why a total of 30 minutes and intervals no smaller than 10 minutes are the magic numbers is as clear as a window during a snowstorm. We just don't know why, but those times appear to be what it takes to change the way certain genes function.
Q: In terms of burning calories, is 11 minutes of stair climbing equal to 36 minutes of walking?
A: Usually, 36 minutes of walking will burn about 200 calories, whereas 11 minutes of stairs will burn around 100. We say "usually" because the burn rate depends on how fast you walk or do stairs. If you have access to a gym, there's an easy way to find out: Mimic your pace on a treadmill and a stair-climbing machine, and see how many calories you burn in those time periods. While the calorie counters on machines aren't perfect, they'll give you a reasonably accurate idea that's better than guessing.
Q: I get lower back pain if I walk, so I'm biking daily. Is it doing me as much good as walking?
A: Most studies don't directly compare biking to walking, but our best estimate is that if you bike with resistance (as if you're going up hills), you will get most of the same benefits. The key exception: Biking won't make your bones stronger. Strengthening your bones (by laying down more calcium and other minerals into them) requires actual contact with the ground: lifting your foot up and then landing on it again. Your body, not your bike, has to support you for your bones to get the message.
Q: After fighting my weight for 35 years, I had gastric bypass surgery in 2006. I have maintained my current weight of 119 for two years, but I can't get motivated to exercise. I get up at 3:15 a.m. and work a full-time job at a hospital lab from 6 a.m. to 2:30 p.m. I'm 59. My husband is 66 and has cirrhosis and is on dialysis, so I am the caretaker. I work and keep my house up, and by the time my day is over, I am ready for bed. How can I fit exercise in?
A: You may already be getting the exercise you need. Find out by clipping on a pedometer and seeing how many steps you walk daily. If you are getting 10,000 steps a day doing your lab job, cleaning, making meals, taking care of your husband and doing all the little extras that life requires, fantastic. If not, but you're reasonably close—and we bet you are—park a little farther from the lab, or get off one bus stop earlier and go one bus stop farther at the end of the day, then walk the difference. Dr. Mike parks in the lot that's farthest from his office and walks about a mile each way just going to and from his car. Of course, Dr. Mike's a little crazy—he tries to do 12,000 steps a day, and if he doesn't, he gets on a treadmill before he goes to sleep. In fact, he just completed 50 minutes on the treadmill—so he's signing off for bed! And no, hip movement in bed doesn't count, and even he doesn't wear a pedometer to bed.
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