Exercise and Fitness

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.

At what age do I need to start regular exercise?

DEAR DOCTOR K: I believe you when you say that regular exercise protects my health. But I'm just 20. For me the question is, when should I begin regular exercise? The diseases that exercise protects against usually don't develop until a person is older than 60. I'd like not to have to worry about exercise for a few decades.

DEAR READER: I wish I could rid you of that worry. But, in fact, if you are not already exercising regularly, you are probably putting your health at risk 30 years from now. Many of the diseases that exercise protects against actually start in young adulthood and take decades to become severe enough to cause symptoms. For example, autopsy studies have been performed on soldiers killed in war -- people your age. They reveal that many already have early signs of atherosclerosis, the cause of heart attacks, strokes and premature death.

Can exercise help prevent back pain?

DEAR DOCTOR K: I get back pain every so often. It can last a week and interferes with my life. Can exercises prevent more attacks in the future?

DEAR READER: Absolutely yes -- IF you do them regularly. Exercise is a great way to prevent repeat episodes of low back pain. The right exercise program will help you build strong, flexible muscles that will be less prone to injury.

Does standing more really make a difference to your health?

DEAR DOCTOR K: Several of my colleagues have switched to standing desks. Does standing really make that much of a difference to your health?

DEAR READER: Research suggests that the more we sit, the more we're likely to develop heart disease and other illnesses, including diabetes and cancer. Whether it's sitting at the computer to get some work done or on the couch watching TV, too many hours spent on our bottoms increases the risk of dying from any cause -- even if you exercise regularly.

What is interval training?

DEAR DOCTOR K: What is interval training? What are the benefits of exercising this way?

DEAR READER: Interval training simply means alternating between short bursts of intense exercise and brief periods of rest (or a less-intense activity). The payoff is improved cardiovascular fitness with shorter workouts. Aerobic activities such as walking, biking, running and swimming make the heart and lungs work harder, which increases cardiovascular endurance.

Can exercise cause sudden cardiac arrest?

DEAR DOCTOR K: My wife saw something on the news about a man who died of sudden cardiac arrest while jogging. Now she doesn't want me to exercise. I'd really love to get my running shoes back on. What can I tell her to ease her worries?

DEAR READER: I read your letter as I was cooling off after exercising. So your question is timely. Your wife's concerns are understandable, but probably misguided. I spoke to my colleague Dr. Aaron L. Baggish, the associate director of the Cardiovascular Performance Program at Harvard-affiliated Massachusetts General Hospital. He confirmed what I thought I knew.

How can I continue my walking program during the winter?

DEAR DOCTOR K: Last year I started a walking exercise program in the spring. But by winter the cold temperatures drove me indoors. This year I'd like to keep walking year-round. Any advice?

DEAR READER: Exercising in winter can be difficult, and many avid walkers get derailed when temperatures drop. But with the right clothing and preparation, almost any type of weather can be walking weather: Warm up indoors. Cold air can make the transition to workout mode tougher. Doing an exercise warmup indoors will take stress off your heart and make winter walking feel easier.

What is it about exercising that promotes good health?

DEAR DOCTOR K: You frequently write that exercising regularly may be the best thing you can do to improve your health. I don't doubt that's true. But have scientists figured out what it is about exercise that promotes health?

DEAR READER: You've asked a very interesting question. Perhaps you're thinking, as do some of my patients, that exercise leads the body to produce certain natural chemicals that promote health. And that if you could make pills out of those health-promoting chemicals, maybe you wouldn't need to exercise. Actually, research here at Harvard in the past few years may have made a step in that direction. The research is primarily in mice, but it probably applies in humans as well.

Will tai chi help my fibromyalgia?

DEAR DOCTOR K: I have fibromyalgia, and my doctor recommends that I start tai chi exercises. Like any exercise, it will take time. So I want to be sure it really might help me. Can it?

DEAR READER: One of the many practices from Asia that have spread to the West in the past 40 years is tai chi. It is often described as "meditation in motion." I think it could just as well be called MEDICATION in motion. This mind-body practice appears to help treat or prevent many health problems. Tai chi is a low-impact, slow-motion exercise.

How can start a safe stretching routine?

DEAR DOCTOR K: At my last appointment, my doctor noticed that my movements have become stiffer. He suggested that I do some stretching exercises daily. Is there anything I should know before I start? I'm in my 80s, and I don't want to hurt myself.

DEAR READER: Our bodies become less flexible as the years roll by. Inflexibility puts a crimp in daily acts, making it harder to walk, raise your arms or turn your head while backing up the car. It undermines balance, too, which can cause life-altering falls. Stretching can help. You'll make the best gains if you stretch frequently -- all or most days of the week. At the very least, stretch two or three times a week.