A Web-based way of tracking your physical activity level

If you want to keep tabs on your activity level and how many calories you're burning without buying a gadget, check out this government Web site: www.choosemyplate.gov It's run by United States Department of Agriculture (USDA). Why is the USDA in the exercise business? Because the department promulgates nutrition guidelines, and good nutrition necessarily involves energy balance, which means making sure that the amount of calories you're taking in should match the number you're burning — and be less if you are trying to lose weight. So although you can't eat physical activity, it's part of the USDA food pyramid. (Locked) More »

Active commuting: It's a win-win-win - and more victories may be in store

Much of the research into physical activity and its effects focuses on what we do in our spare time — and for some good reason. Workplace tasks are increasingly sedentary: many people stare at computer screens all day, with only their fingers moving. And getting to the job has become a rather slothful enterprise: a few steps to get behind the wheel and then a few more to get from the parking lot to the office. But with rising gas prices and clogged roadways, biking or walking to work has come into vogue. Physically active commuters save money and "hardwire" physical activity into their days. (Locked) More »

Glossary of exercise terms

If you're considering starting an exercise regimen, all the jargon you're likely to encounter can be intimidating. Should your exercise be aerobic or anaerobic, isotonic or isometric? What's a MET, and do you need to know your BMR and your VO2 max? To ease any linguistic anxiety, here's a quick review of some common exercise terms and concepts. Exercise falls into two general categories: aerobic and anaerobic. Aerobic exercise is muscle movement that uses oxygen to burn both carbohydrates and fats to produce energy, while anaerobic exercise is muscle movement that does not require oxygen and only burns carbohydrates to produce energy. In practice, aerobic exercise means activities such as walking, bicycling or swimming that temporarily increase your heart rate and respiration. Aerobic exercise (also known as cardiovascular exercise) builds your endurance. (Locked) More »

Why is exercise protective against cancer?

Many studies show that people who are physically active are less likely to cancer. Such associations don't prove that exercise prevents cancer. But they are a hint. And if there's a biological explanation for a protective effect, the case gets that much stronger. Here are several biological explanations mentioned in the Physical Activity Guidelines Advisory Committee (PAGAC) report, which laid the scientific groundwork for the new set of exercise guidelines due out in October 2008. There's still quite a bit of conjecture involved, but you can see why exercise might keep some people out of harms way of cancer. (Locked) More »

Editor's note

Anthony L. Komaroff, M.D., editor in chief of the Harvard Health Letter, introduces a special issue focused on exercise. (Locked) More »

Why we should exercise - and why we don't

It's easy to find reasons not to exercise, but it's also relatively easy to meet the recommended guidelines for physical activity. Here are 27 suggestions for ways to be more physically active. (Locked) More »

Can a gadget get you going?

The Heart Letter evaluates three devices that provide information and feedback about physical activity: a pedometer, a heart rate monitor, and an activity monitor. (Locked) More »

Meet the METs

A MET is a metabolic equivalent, a measure of how much energy is expended doing a given exercise or activity. Researchers gauge levels of physical activity in METs. A chart shows various activities and how many METs they expend. (Locked) More »

The gender divide

Women are at higher risk than men of tearing the anterior cruciate ligament of the knee. Part of this disparity may be due to anatomical differences, and hormones may play a role as well. (Locked) More »

Let's talk to an expert

Dr. I-Min Lee, a member of the government committee that helped establish new guidelines for recommended amounts of physical activity, discusses fitness and exercise. (Locked) More »