Exercise and Fitness

Can teens help prevent diabetes through exercise?

DEAR DOCTOR K: My teenage son doesn't like sports or exercise. Diabetes runs in our family. You say exercise protects against diabetes and is valuable even in young adults. Can you give me some ammunition to convince my teenager to exercise?

DEAR READER: Perfect timing: A new study has been published that provides an answer. Most studies of exercise have been in adults, often older adults. Until this recent study, there wasn't a lot of information about teenagers.

How does physical exercise improve brain health?

DEAR DOCTOR K: You say that physical exercise helps to improve brain health, but it's not obvious to me how that could be. Do researchers understand exactly how exercise helps the brain?

DEAR READER: I understand why that's puzzling. It's easier to see how regular moderate exercise could protect against heart disease, for example. The heart is a muscle, and exercise makes the heart exercise.

Is jogging or brisk walking better for my health?

DEAR DOCTOR K: I'm a 42-year-old couch potato. Gentle pressure from my wife and doctor have "convinced" me to start exercising regularly. What's better for my health: jogging or brisk walking?

DEAR READER: If you're a couch potato, you're in the majority. A recent study found that nearly 60 percent of adults in the United States do not get enough exercise.

Will weight training help reduce diabetes risk?

DEAR DOCTOR K: I have a family history of diabetes, and I'd like to do what I can to reduce my risk. My doctor says aerobic exercise will help, but I prefer weight training. Could that help too?

DEAR READER: Exercise, particularly aerobic exercise, helps to reduce the risk of Type 2 diabetes, which is by far the more common type of diabetes. So I assume that's the type that runs in your family.

Is exercise good for the brain?

DEAR DOCTOR K: I do both aerobic exercises and resistance (strength) training exercises. Recently I heard that aerobic exercise might be better for the brain. Is there any truth to that?

DEAR READER: You probably are referring to a study published in February 2016 that got a lot of media attention. Before getting into the details of that study, it's worth talking more about exercise and the brain.

Can children benefit from yoga?

DEAR DOCTOR K: My 8-year-old daughter has expressed an interest in taking a yoga class, but I don't want to waste my money. Can children really benefit from yoga?

DEAR READER: Yes, they can. I spoke to Dr. Marlynn Wei, who is a psychiatrist, certified yoga teacher, and author of the upcoming Harvard Medical School Guide to Yoga. She noted that yoga and mindfulness (a related practice) have been shown to improve both physical and mental health in children.

I have painful knees. Is swimming a good exercise option for me?

DEAR DOCTOR K: I'm overweight, and I want to exercise. But I have painful knees that make it difficult to walk. Is swimming a good alternative?

DEAR READER: In terms of convenience, it's hard to beat brisk walking as a form of exercise. You don't need any special equipment or venue, and you can do it in many places. But during the winter, harsh weather can make walking outdoors unpleasant -- even treacherous at times. And for some people -- such as those with achy knees, sore hips or substantial weight -- walking may be uncomfortable.

Is there any evidence that mobile health apps actually work?

DEAR DOCTOR K: There are so many health-oriented apps for mobile devices these days. But is there any evidence that they actually work?

DEAR READER: The number of health-related apps for mobile devices has exploded in recent years. The most popular ones monitor physical activity. Others deliver helpful reminders or information through text messages. Various apps aim to help you lose weight, monitor your blood pressure, manage your diabetes or quit smoking.

How can I adjust my walking routine to start losing weight again?

DEAR DOCTOR K: When I first started walking for exercise, I lost some weight. Since then, my weight has plateaued. How can I adjust my walking routine to start losing weight again?

DEAR READER: To reignite your weight loss, you need to keep challenging your body. That means walking farther, faster and more often. The more vigorous your workout, the longer you'll continue to burn calories after you stop exercising.