Exercise your right to health
your right to health
Don’t let inconsistent guidelines
on how much or what kind of exercise is best
for your heart keep you seated in frustration.
(This article was first printed in the July
2004 issue of the Harvard Heart Letter.
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There isn’t an official “best” way
to exercise if you want to control or prevent
heart disease. And sometimes it seems as though
there aren’t even consistent recommendations
for how much to exercise.
For years, exercise was supposed to be hard:
a no-pain-no-gain regimen of high-intensity activity
aimed at pushing the heart and lungs to their
limits. Then, in 1995, experts unveiled a kinder,
gentler approach: 30 minutes or more of moderate-intensity
activity done on most, preferably all, days of
the week. Brisk walking and leaf-raking joined
jogging and swimming as acceptable activities.
With this no-sweat version, you don’t even
have to be active for 30 minutes straight — 10-
and 15-minute segments are fine. The emphasis
on moderate activity was aimed, in part, at helping
people who wouldn’t exercise vigorously
harvest the health benefits of regular activity.
But just as we were getting used to the idea
of moderate exercise, the Institute of Medicine
told us we needed 60 minutes a day of vigorous
Which one is it — 30 or 60 minutes? Moderate
or vigorous activity? Here are some exercise
basics that we hope will clear the air and help
you pick an exercise or activity that’s
right for you.
How many steps
to good health?
Can a device designed by Leonardo da Vinci
matched with an easy-to-remember goal keep
you fit and healthy?
One of da Vinci’s many inventions
was a simple, pendulum-powered device for
counting steps. Its electronic descendants,
called pedometers, are now featured in
programs sporting the 10,000 Steps a Day
slogan. They are being promoted by government
and public health officials. Even McDonald’s
is getting into the act by offering a pedometer
with its new “Go Active! Happy Meal.”
Pedometers are small, pager-sized devices
that clock every step you take when clipped
to a belt or pocket. Some let you program
in the length of your average step in order
to measure how far you’ve walked.
Others tally up “aerobic steps”— continuous
steps taken for more than 10 minutes at
Pedometers are inexpensive ($5–$40),
easy to use, and give you useful information
about yourself. Wearing one for a week
or so can help you get a handle on how
active you are. Once you’ve figured
out your average daily steps, the device
can help motivate you to take more.
Should you aim for 10,000 steps a day?
Not necessarily. That’s too high
a goal, at least initially, if you aren’t
used to walking or have a chronic condition
that limits your activity. Several small
studies show that some people who take
10,000 steps a day don’t move fast
enough to meet the 30 minutes of moderate
activity goal, while some exercisers who
more than meet the goal never rack up 10,000
In other words, the quality of
your steps, not the quantity, is what’s
important. Walking briskly for at least
30 minutes a day, either in a single stretch
or two or three shorter ones, will do more
for your heart, lungs, and the rest of
you than taking 10,000 leisurely steps.
Resolving the conflict
Let’s tackle the time and intensity questions
first. The 1995 recommendation, which has been
endorsed by the Surgeon General, American College
of Sports Medicine, American Heart Association,
and other groups, still stands as an excellent
starting point for warding off a heart attack,
stroke, or premature death. If you already have
heart disease, it’s a great way to fortify
your heart against future trouble.
The Institute of Medicine’s recommendation
rightfully acknowledges that 60 minutes of exercise
a day is better than 30 minutes. What’s
more, the Institute focused on losing weight
or maintaining a healthy weight, both of which
require burning extra calories.
Calories burned are the key
If you aren’t active at all, any amount
of exercise or physical activity is a step in
the right direction. A walk around the block,
even if you need to stop a few times to catch
your breath, trumps sitting by a long shot. Climbing
the stairs beats taking the escalator at the
mall or at work.
If you’re already somewhat active, the
more exercise you get, the better. A landmark
study of 17,000 Harvard alumni suggests that
men who burn an extra 700 or so calories a week
by walking, playing sports, or doing some other
form of dynamic exercise live longer than those
who aren’t active (see Harvard Alumni
Study below). The health benefits continue
to increase up to about 2,000 or so calories
a week, then seem to level off from there. Information
from a long-term study of female nurses shows
similar trends for women.
A long-term study of Harvard graduates
showed better survival with burning about
2,000 calories a week, the equivalent of
walking 3 miles a day.
Tallying up calories burned isn’t something
you can do on the fly. It depends on your weight,
the intensity of an activity, and how long you
do it. Here are a few benchmarks, all given for
a 155-pound person:
• Walking briskly (at 4 miles per hour)
for 30 minutes burns 150 calories.
• Heavy cleaning for 45 minutes burns 250
• An hour of singles tennis burns 300 calories.
We’ve posted a much longer list for three
different weights on our Web site, health.harvard.edu/heartextra.
A word of caution here: Intensity matters. Sauntering
through the mall for 15 minutes beats sitting,
but it doesn’t make the grade as exercise
for anyone who is active. For an activity to
help your cardiovascular system, it must make
your heart beat faster and speed up your breathing.
What’s the difference between physical
activity and exercise? Both involve three
Ms: movement, muscles, and metabolism.
Physical activity is any movement that
involves muscle contractions and an increase
in metabolism. It includes everything from
housework to marathon running. Exercise
is a specific kind of physical activity — one
done purposely to improve health and physical
Vary the dimensions
You can hit a target such as 2,000 calories
a week many different ways. Adjusting the three
dimensions of exercise — intensity, duration,
and frequency — lets you pick activities
that suit your lifestyle and personality. Intensity is
how hard you exercise. It’s measured in
calories burned per minute. Duration refers
to how long you exercise, while frequency refers
to how often.
Brief sessions of an intense activity (vigorous
activity) can burn the same number of calories
as longer or more frequent sessions of a less
intense one (moderate activity). Say you prefer
to keep your bouts of exercise short and sweet.
A high-intensity activity such as tennis or vigorous
cycling might be right for you. If intense isn’t
your thing, pick a less vigorous activity that
you can do more often or for longer periods.
Many examples are posted at health.harvard.edu/heartextra.
Topple your exercise barriers
It’s one thing to say, “Just do
it.” It’s another to actually get
moving. Cars, labor-saving devices, televisions,
and other machines and gadgets — even the
design and layout of our communities — can
subvert the need for muscle power and seduce
us into sitting rather than moving.
Personal barriers also limit activity. These
range from lack of time for exercise to worries
that exercise will cause a heart attack or injury
and limited access to parks, sidewalks, bicycle
trails, or safe and pleasant walking paths.
If you want to exercise but have trouble getting
started or sticking with it, try taking the “Barriers
to Being Active” quiz from the National
Center for Chronic Disease Prevention and Health
Promotion. It can help you identify some of the
things standing in your way.
Surmounting barriers such as lack of time or
disliking exercise takes creative thinking about
making time for physical activity and finding
an activity you can enjoy. Dealing with other
issues, like worrying that exercise will give
you a heart attack, takes some education. Barriers
like not having access to safe walking paths
or exercise facilities may call for downright
You don’t have to leap the barriers standing
between you and a more active life. Instead,
try putting one foot in front of the other and walking around
Options for exercise
Many exercise recommendations emphasize walking.
And why not? It’s free, easy, doesn’t
require special training or equipment, and can
be done anytime and anywhere. Plus dozens of
studies show that walking can prevent or help
control high blood pressure, high cholesterol,
heart disease, diabetes, peripheral artery disease,
heart failure, and a host of other conditions.
As a bonus, walking is a weight-bearing exercise
that can help prevent osteoporosis.
More interested in sports than walking? Tennis
is a good option. In addition to being an aerobic
sport that gives your heart and lungs a workout,
it can be played at many different levels and
well into old age.
If you’d rather get your exercise in a
club, you’ll burn the most calories on
a treadmill. Stair-steppers, rowing machines,
and cross-country trainers come next, all ahead
of the standard stationary bicycle.
Aim to burn an extra 2,000 calories a week.
It doesn’t really matter how, as long as
you find something other than your true love
that moves you and gets your heart beating faster.