Exercise and Fitness

How do I know if I’m pushing myself too hard while exercising?

DEAR DOCTOR K: I like really intense exercise, so I expect things to hurt when I'm working out. How do I know if I'm pushing myself too hard?

DEAR READER: The expression "no pain, no gain" has misled many an exercise enthusiast. The fact is, pain and other symptoms during exercise are not normal. You should pay attention when your body is sending you warning signs. Let's start with what you should expect. At the height of a workout, you should be breathing a little harder. You should still be able to talk, but you shouldn't be able to sing. You should feel your heart beating faster than normal during exercise. And you may feel your muscles burn a little as they work hard for you.

If I exercise less than the recommended 150 minutes/week, will it still benefit my health?

DEAR DOCTOR K: You often recommend exercising for 30 minutes a day, most days of the week. That target intimidates me. Is it worth it for me to exercise less, say 15 minutes, three days a week? Or is there no benefit unless I commit to the full 150 minutes per week?

DEAR READER: I'm glad you asked that question, because there are a lot of people who are daunted by the thought of exercising that much -- and therefore don't do it at all. It is true that I do advise 150 minutes of moderate-intensity activity each week. But two recent studies, while not changing my view that 150 minutes is best, show that less than this still brings benefits.

Can dogs improve our health?

DEAR DOCTOR K: I'm on the fence about getting a dog. My wife claims that pets -- particularly dogs -- can improve our health. Is that true?

DEAR READER: When I was growing up, there was always a dog in the family. And I mean "in the family": They were a part of the family, often coming with us when we went on errands. Some of my friends never had a pet, so I once asked my mother why we always had a dog. She replied: "Dogs are good for us." I remembered that answer when I got your question.

Is it important to know your heart rate when you’re exercising?

DEAR DOCTOR K: I've seen fitness monitors that track heart rate. Is it important to know your heart rate when you're exercising?

DEAR READER: Whether you're just getting started with an exercise routine or are a committed fitness enthusiast, tracking your heart rate can be helpful. Heart rate monitors -- which instantly tell you how fast your heart is beating -- can help you exercise at the right intensity.

What helps us balance?

DEAR DOCTOR K: What are the body parts, or systems, that help us balance?

DEAR READER: You're asking a very interesting question. I never even thought about it until I went to medical school. When I learned what I'm about to tell you, I thought it was interesting. However, I didn't appreciate how important problems with balance would be for my patients.

Should I stretch before or after I exercise?

DEAR DOCTOR K: I've been running for years and have always stretched before my morning run. Now I hear that I shouldn't stretch first. Why not?

DEAR READER: You should stretch before your run -- but perhaps not the types of stretches you've been doing. Static stretches are what most people have traditionally done, both before and after exercise. Static stretches involve adopting and holding a position that stretches a muscle or group of muscles.

How does strength training slow bone loss?

DEAR DOCTOR K: I was recently diagnosed with osteopenia. My doctor advised strength training because it can help slow bone loss. How does it do that?

DEAR READER: Osteopenia is a thinning of the bones. It is often a precursor to osteoporosis, a more severe thinning of the bones. Osteoporosis puts you at risk for disabling, and sometimes debilitating, fractures. Bones are filled with cells. Some cells build up new bone; other cells tear down old bone. In most people, those two processes are in good balance.

Will a digital fitness monitor help me become more active?

DEAR DOCTOR K: I'd like to be more active. Do you think a digital fitness monitor will help?

DEAR READER: When digital fitness monitors (DFMs) became available several years ago, I was initially skeptical. I figured they would be the latest example of our fascination with electronic devices and that people would quickly tire of them. Well, surveys show that some people have quickly tired of them and left them to collect dust in a drawer.

Is watching TV the worst sedentary activity for our health?

DEAR DOCTOR K: Is watching TV worse for your health than any other activities that keep you from being active?

DEAR READER: We know that exercise is good for our health, and that too much inactivity is bad for our health. But does it make sense that watching TV is worse than other sedentary activities? Actually, it may. My colleague Dr. Robert Shmerling is an associate professor of medicine at Harvard Medical School. He noted that a recent study shows watching a lot of TV is worse for your health than other activities that involve long periods of sitting. The study Dr. Shmerling referred to enrolled more than 13,000 young and middle-aged adults. Researchers asked the study subjects how much time they spent watching TV, using a computer and driving.

Is it possible to go off blood pressure medication through diet and exercise?

DEAR DOCTOR K: Is it possible to get off blood pressure-lowering medication through diet and exercise?

DEAR READER: Yes, it is. I've seen many patients commit to lifestyle changes and get off blood-pressure medicines entirely. More often, I've seen that a commitment to a healthier lifestyle allows people to greatly reduce how much medication they take, even though they still need some medicines to control their blood pressure. While many people, myself included, would like to not have to take medicines at all, being able to reduce the dose is a big deal. Many of the side effects of medicines are reduced or eliminated by reducing the dose.