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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:
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.
Much of the research into physical activity and its effects
focuses on what we do in our spare time — and for some good
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.
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.
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
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.
Anthony L. Komaroff, M.D., editor in chief of the Harvard Health
Letter, introduces a special issue focused on exercise.
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
The Heart Letter evaluates three devices that provide information
and feedback about physical activity: a pedometer, a heart rate
monitor, and an activity monitor.
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.
Whether mild or strenuous, a youg workout provides fitness
benefits to almost anyone, even older people and those who have
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.
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.