A Leading Cardiologist’s Exercise Formula for a Healthy Heart

A Leading Cardiologist’s Exercise Formula for a Healthy Heart

Here’s how often and how long you should work out for optimal cardiovascular fitness.

By Suzanne Steinbaum, DOUpdated February 25, 2022


Most people have been told by a doctor that regular exercise is good for their heart health. But what does “regular exercise” really mean? Working out for an hour twice a week? Or four days a week? Every single day?

As a preventive cardiologist, I hear these questions a lot and here’s what I tell my patients: As a general rule, I believe that it’s more important to work out frequently than it is to work out for long durations of time. More specifically, I recommend exercising for at least 30 minutes, five days a week—and so does the American College of Sports Medicine. This exercise formula gets you to the minimum amount of cardio recommended by the American Heart Association to support heart health and reduce your risk of cardiovascular disease.

Why Do Frequency and Consistency Outweigh Duration?

Dedicated physical activity five times a week means that you almost never go more than a day without moving your body. Yes, recovery time is important after major training or bursts of activity. But to build stamina and fitness, it’s best if your muscle fibers and your metabolism don’t return to baseline completely between workouts.

People who exercise regularly may have better blood sugar control, a key factor in heart health since elevated blood sugar increases inflammation and the risk of cardiovascular disease. Exercise prepares your body’s cells to take in glucose (read: energy) more easily from the food you eat, naturally reducing the amount of sugar that’s left over in your bloodstream. In fact, one exercise session can result in lower blood sugar for up to 12 hours. The more you exercise, the more often you get this blood sugar benefit.

Add This Exercise to the Mix

High-intensity interval training, or HIIT, workouts are popular for a reason: Studies suggest that these types of workouts can deliver the same health benefits of a moderate workout in half the time. It’s true, but only if you strike the right balance and work out on a consistent basis.

In a recent study, researchers strapped blood sugar monitors and other monitoring equipment to two small groups of men. One group did 10 to 15 minutes of HIIT riding on a lab bike three times a week. The other group did 30 to 40 minute rides at a moderate pace five times a week. At the end of six weeks, everyone’s cardiovascular fitness improved, but the five-day exercisers had better blood sugar control and lower blood pressure than the folks who worked out harder and less often.

I must point out that the HIIT sessions in this study aren’t like the ones I recommend to my patients. The participants did 30-second all-out sprints followed by two minutes of rest, then repeated that effort four to six times, with a work-to-rest ratio of 1:4.

Several studies suggest that an ideal HIIT work-to-rest ratio is 2:1, where you work hard for, say, two or four minutes vs. an all-out sprint at about 85 to 95 percent of your peak heart rate. Then you slow down for one or two minutes. A solid HIIT workout usually lasts 20 to 30 minutes, like many of the high-intensity classes offered on the Peloton App.

HIIT is a great tool if your doctor gives you the go-ahead. I often recommend them to patients who are in excellent condition, have grown bored with their usual routines and can push themselves a little harder. But HIIT is not a five-day-a-week type of workout. Because these exercise sessions are more exhaustive than moderate ones, your body needs more time to recover and there’s likely a limit to how many you can do safely each week.

A small new Swedish study found that people who began doing strenuous workouts most days a week for an entire month had steep drop-offs in blood sugar control and the health of their mitochondria—the energy-storage batteries inside each cell in your body.

When incorporating HIIT into your routine, aim for no more than three sessions per week if you’re already relatively fit. Peloton instructors always put safety first, but to be doubly sure this exercise is right for you, always check with your doctor before beginning any new exercise program.

The Bottom Line About Exercise and Heart Health

For a healthier heart, get at least 150 minutes of physical activity a week, ideally moving your body for five out of the seven days. Make one or two of those workouts a HIIT if you want to change things up, but always listen to your body. It is possible to get too much of a good thing.

Many of my patients are high-achievers, both at work and in their other pursuits such as fitness and sports—kind of like the Peloton community. Remember, it can be easy to get caught up in trying to do things so “right” that you lose the joy of doing them. The absolute best workout for your heart is the one that you will enjoy and do consistently.

Dr. Suzanne Steinbaum is a leader in preventive cardiology, now in private practice in New York, and is a paid consultant of the Peloton Health and Wellness Advisory Council. She is the CEO/Founder of Heart-Tech Health, a technology-based prevention model. She published Dr. Suzanne Steinbaum’s Heart Book: Every Woman’s Guide to a Heart Healthy Life, and has been a national spokesperson for Go Red through the American Heart Association for 18 years. Follow her on Instagram and Twitter.

This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.