Ask Well

Ask Well

The New York Times answers readers’ health queries in its Ask Well column. Here are a few excerpts. To ask a health question,go to http://well.blogs.

Are there exercises to ward off dementia?

I am 66 years old and exercise four times a week. How much or what kind of exercise should I do in addition to cardio to maintain brain health and ward off dementia?

You might want to add several weight-training sessions every week. Endurance exercise is undoubtedly good for the brain,with studies in lab animals showing that moderate aerobic exercise,the equivalent of jogging,doubles or even triples the number of new neurons in the brain’s memory centre,compared with the brains of sedentary animals. So keep up the cardio training. But other recent science suggests that resistance training also has brain benefits that may be unique,meaning that if you don’t lift weights,you could be missing out. In a particularly relevant 2012 study,rats with weights tied to their tails climbed ladders to simulate resistance training,while others ran on little treadmills or didn’t exercise. After eight weeks,the brains of the weight-lifting and treadmill-running rats were subtly different. The weight trainers showed higher levels of one particular brain protein than the runners or the sedentary animals,and the runners’ brains now displayed higher levels of another protein. It appears that the best way to benefit your brain is to practice both endurance and weight training.

Double the workout,double the benefits?

If I do 30 minutes of cardio exercise six days a week,would increasing it to 60 minutes a day be twice as good for me?


If you’re asking whether doubling exercise time doubles the health benefits,then,by most indications,it does not — though it does increase them slightly. In a notable study from 2011,people of all ages who exercised very moderately,for about 15 minutes a day,or approximately half of your current regimen,reduced their risk of dying prematurely by about 14 per cent,or the equivalent of three additional years of life. Those whose workouts were twice as long — like yours,30 minutes per day — saw an additional drop in the risk of premature death,but only by 4 per cent. Exercise beyond a certain level may even be counterproductive. In other words,you are probably doing the ideal amount of exercise,if your goal is to live to be 82.

Getting in shape in middle age

What is a good exercise plan for a middle-aged person who is out of shape (assuming good health other than the lack of fitness)?

“It’s a movable feast’’ in terms of workout options,says Dr. Michael Joyner,a physiologist at the Mayo Clinic in Rochester,Minnesota. Pedal or swim if you have a bike or gym membership. But walking is,physiologically and logistically,the simplest exercise,Dr. Joyner says. Just put on comfortable sneakers — they don’t need to be new or expensive — and set off. Try to walk for half an hour. These 30 minutes do not need to be completed in one chunk,either. It is fine to break up the exercise during the day “into smaller bites,’’ Dr. Joyner says. And in fact,for certain groups of people,it’s probably more effective to do so. Or just do push-ups and squats in your living room. Start with one push-up,if that’s all that you can do,and progress to 15 or 20. — Gretchen Reynolds