High Blood Pressure
High blood pressure (or “hypertension”) produces no obvious symptoms until it reaches
the advanced stage and damages organs, especially the kidneys, heart, brain, and
blood vessels. It is one of the most common risk factors for heart attack, stroke, kidney
failure, peripheral vascular disease, atherosclerosis, and heart failure, defined as an
inability of the heart to pump enough blood to meet the body’s needs.
Untreated, it can also lead to left ventricular hypertrophy (LVH), an enlargement and
thickening of the walls of the heart’s main pumping chamber. LVH is an independent
risk factor for heart failure.
In general, high blood pressure is defined as consistent blood pressure readings
above 140 / 90, although 120 / 80 is the goal.
Doctors have long debated the role of stress in promoting heart disease, but
there’s a growing body of evidence that it is a risk factor. Exactly how stress
harms the heart is not fully understood, but researchers do know that constant
high levels of stress prompt hormonal changes that can send blood pressure and
insulin levels soaring, and likely promote inflammation and other body changes
that, over time, increase cardiovascular risk. Stress may also lead to depression,
one of several psychological factors linked to an increased risk of a heart attack.
Both short-term and prolonged stress appear to be risk factors. Many heart
attack patients report undergoing unusual stress in the hours before they were
stricken. It is well-known that sudden, severe stress can precipitate a heart attack
in people who already have coronary disease.
Sustained stress has also been associated with an increased heart-attack risk.
This connection was documented in a recent multinational study that surveyed
more than eleven thousand people who had suffered heart attacks and compared
them with about thirteen thousand healthy control subjects. The study
found that the heart-attack patients had been under much more stress in the
previous year than had been the healthy controls. The stress came from various
sources — problems at work, financial difficulties, family troubles, depression,
the death of a loved one, and other causes. The senior investigator of the study,
Dr. Salim Yusuf of McMaster University, concluded that stress “was comparable
to risk factors like hypertension and abdominal obesity,” and that its effect was
“much greater than we thought before.”
Of course, all of us are subjected to different types of stress every day, and
most people can develop moderately effective ways of dealing with it. Yet the presence
of other risk factors and a person’s personality make everyone’s experience
of stress unique. A hard-driven executive may thrive on a stress level that would
drive other people crazy. Conversely, even low levels of stress may tip the balance
for a more high-strung person. In any event, persistent stress and poor coping
mechanisms can harm health.
Several studies published in the last few years have identified depression as an
independent factor that increases the risk of a heart attack. Precisely how depression
affects heart function is unknown, but diagnosing and treating depression is now
considered an important aspect of reducing cardiovascular risk.
Numerous studies have found that exercise is an important factor in preventing
heart disease. People who exercise regularly are less likely to be overweight and
develop other cardiovascular risk factors, including diabetes, high blood pressure, and
elevated blood cholesterol. But even though most people know that regular exercise is
beneficial, many have difficulty sticking to a regimen. Arthritis and other orthopedic
problems, weight, weather, geographic locale, time constraints, and availability of
exercise facilities are just some of the obstacles to a successful exercise program.
Indeed, we all can probably come up with a long list of excuses to remain a sedentary
“couch potato,” but in fact virtually everyone can develop an exercise program that fits
his or her lifestyle. If you have arthritic knees, jogging or singles tennis is not going to be
part of your long-term exercise regimen. But you may well consider swimming, tai chi,
using an elliptical trainer, or any number of other enjoyable activities.
The Three Variables of Every Exercise Program
Three variables influence the beneficial or training effect of exercise:
Aerobic activities that require moderate exertion over an extended period are
the most effective for improving cardiovascular function.
To obtain maximum benefits, we recommend that you exercise for an average
of thirty minutes three to five days a week. (You may exercise longer or more
frequently provided that doing so does not provoke symptoms or complications.)
The more intensive the exercise, the greater the cardiovascular conditioning.
Most healthy adults should strive for five weekly sessions, and those who
need to lose weight should plan five or six low-impact workouts a week. (As a
general rule, you should refrain from exercise one or two days a week to give the
body a chance to recover.) The duration varies according to individual factors
and the type of exercise. A sedentary person just starting a regimen may be well
advised to start with one or two ten-minute sessions three times a week and to
gradually increase the intensity and duration as endurance improves. The type
of exercise also influences how long you should exercise. Walking or jogging a
mile burns about a hundred calories, regardless of how fast or slow you go. For
example, walking a mile in twenty minutes burns the same number of calories
as running a mile in ten minutes. Thus, if the goal is to burn three hundred
calories, you can achieve this in a half hour of running at a rate of six miles per
hour, or an hour of walking at three miles per hour.
As for intensity, the goal is to exercise at a certain percentage of your maximum
safe heart rate, depending on your general health, age, and cardiovascular
risk factors (see Box 3). In general, an obese or older person should exercise at a
more moderate pace; for example, start at 50 or 55 percent of the maximum safe
heart rate and gradually increase this over time. You’ll soon learn what is
comfortable for you. As a rule of thumb, many experts recommend adopting a
“talking pace,” which is intense enough to raise your heart rate and produce
sweating but moderate enough that you can carry on a conversation without
gasping for breath. At first, you may be able to achieve this pace only while
walking at a moderate pace, but as your fitness and endurance improve, you’ll be
able to pick up the pace without feeling out of breath.
Warming up before exercise and cooling down afterward will help avoid injury
and discomfort. We recommend five to ten minutes of warm-up exercises—
for example, walking at a moderate pace, swinging the arms, or slow jogging in
place—at the beginning of each session. An older person may need an even
longer warm-up. Some people do stretches during their warm-up, but do so with
great caution, if at all, because stretching cold muscles increases the risk of injury.
How you conclude an exercise session is also important because stopping
abruptly can result in muscle cramps and/or a drop in blood pressure and
dizziness, especially in older persons. So at the end of the session take five or ten
minutes (or longer if you wish) to cool down by exercising gently—for example,
walking at a slow pace—until your heart rate is again ten to fifteen beats a minute
faster than your normal resting pulse. Gentle stretching exercises should also be
part of the cool down period.