We all know that exercise is good for the heart, but do you know how much to do and what benefits to expect?

“A large number of epidemiological studies have consistently demonstrated that regular physical activity reduces the risk of heart attack, stroke, sudden cardiac death, atrial fibrillation, and congestive heart failure,” says Howard Sesso, an epidemiologist at the Harvard T.H. Chan School of Public Health.1 (Atrial fibrillation is an irregular heart rhythm.)

What one of the longest studies of physical activity found

The Nurses’ Health Study tracked more than 72,000 women aged 40 to 65 for eight years.2 Those who walked briskly for three or more hours a week were 35 percent less likely to suffer a heart attack or die from coronary heart disease than those who walked infrequently.

“Ideally, the greater the intensity of physical activity the better,” notes Sesso. “So the more you sweat the better.”

But no sweat doesn’t mean no benefit. Walking around the block or hitting a shopping mall is better for your heart than sitting around the house.

Don’t worry if you can’t do too much activity at one time

“It’s the total amount that matters,” says Sesso. “If you have time for only a half-hour brisk walk during lunch and then another half-hour walk at the end of the day, you’ll essentially get the same benefit as taking an hour-long walk.”3

Exercises like walking helps the heart pump more efficiently, explains Sesso. It also improves the strength of the heart and the way blood vessels respond to increased demands on the heart.

Worried that exercising more might trigger a heart attack?

“The rate at which that happens is quite low, and should not preclude exercising in the first place,” notes Sesso.

“And if you’ve had a heart attack or some sort of cardiovascular procedure, cardiac rehabilitation programs do a great job monitoring and ensuring that the types of exercises that are being done are safe.”

While walking is the most natural way to begin to exercise, says Sesso, you can do whatever you enjoy.

“It can be sports, going to the gym, social activities like dancing, or joining a walking group and doing a daily route.”

How to ramp up the intensity gradually

“Walking at even a slow pace improves cardiovascular fitness,” says Robert Ross, an exercise physiologist at Queens University in Canada. Ross led a six-month study of treadmill walking in 300 sedentary obese middle-aged adults.4

While slow was fine, “the more they walked and the higher the intensity, the more their fitness improved,” says Ross.

“Our participants were struck by how easy it was to ramp up the intensity of their walking by simply raising the incline of the treadmill by 1 or 2 percent. That’s an amount that is hardly perceptible, but it makes a big difference.”

How much exercise to do

So how much should you walk or do other exercise? Here’s what the government’s Physical Activity Guidelines for Americans recommend for adults:

To improve your health, do 150 minutes a week of moderate-intensity aerobic activity like:

  • walking briskly (3 mph or faster, but not race-walking)
  • water aerobics
  • bicycling slower than 10 mph
  • doubles tennis
  • ballroom dancing


75 minutes a week of vigorous-intensity aerobic activity like:

  • race-walking, jogging, or running
  • swimming laps
  • singles tennis
  • aerobic dancing
  • bicycling 10 mph or faster
  • jumping rope
  • hiking uphill or with a heavy backpack

To improve your health even more, increase your activity to 300 minutes a week of moderate-intensity OR 150 minutes a week of vigorous-intensity activity. If you go beyond either, you’ll gain even more health benefits.

The guidelines also recommend that adults do muscle-strengthening activities (like lifting weights or using resistance bands) that work all major muscle groups at least twice per week.


1Br. J. Sports Med. 42: 238, 2008.

2 New Engl. J. Med. 341: 650, 1999.

3 Circulation 102: 981, 2000.

4 Ann. Intern. Med. 162: 325, 2015.

Photos: © Blend Images/fotolia.com (women), © yanlev/fotolia.com (treadmill).