Hypertrophic cardiomyopathy (HCM) is a genetic condition that causes the left ventricle of the heart to become thick and stiff, preventing blood from circulating. Although HCM doesn’t always lead to noticeable symptoms, it’s the most common cause of sudden cardiac death in people under 35 (including young competitive athletes). In addition, about 50 percent of deaths from HCM happen during or after some type of physical activity.

Understandably, this statistic prompts many people with HCM to wonder whether they’re better off avoiding exercise altogether. Studies show that only around 45 percent of individuals with HCM get adequate physical activity. However, with a few precautions, you can reap the benefits of an active lifestyle for your mental health, cardiovascular system, and quality of life.

Following are some valuable tips to consider if you’re interested in exercising with HCM.

1. Monitor Your Target Heart Rate

Cardiologists used to advise individuals with HCM to avoid exercise, but that guidance has evolved over the years. Doctors now advise that people with HCM speak with their health care providers about creating exercise programs tailored to their abilities and limitations. Exercising can help individuals with hypertrophic cardiomyopathy avoid additional heart problems associated with a sedentary lifestyle, like hypertension (high blood pressure) and high cholesterol.

Although it’s important to work with your cardiologist on an exercise prescription based on the severity of your condition, there are general considerations for most people with HCM. Typically, exercise shouldn’t exceed 60 percent of heart rate reserve (HRR). Your HRR is calculated by subtracting your resting heart rate from your maximum predicted heart rate. Resting heart rate describes how many times your heart beats per minute when resting (like first thing in the morning before getting out of bed).

You can calculate your maximum predicted heart rate by subtracting your age in years from the number 220. You can then simply subtract your resting heart rate from your maximum heart rate to get your heart rate reserve.

To measure your heart rate:

1. Firmly press the three middle fingers of one hand against your wrist, neck, elbow, or the top of your foot. Apply enough pressure that you can feel a gentle pulsing sensation.
2. While watching a clock or timer, count how many “beats” you feel for 30 seconds.
3. Double that amount, and you’ll know your heart rate per minute.

You could also use one of the more high-tech alternatives to measure your heart rate. For instance, some wearables, like an Apple Watch or a chest strap created for fitness monitoring, can help you keep a digital record of your heart rate that you can then share with your cardiologist.

Once you know your HRR, you can take steps to ensure that your target heart rate doesn’t exceed 60 percent of this number during exercise.

If you’re not sure how to calculate your heart rate reserve or want reassurance, ask your health care provider for help at your next follow-up visit.

2. Confirm Safe Exercises

Once you know your target HRR and you have a way to track it, you can create an exercise plan in partnership with your cardiologist that allows you to safely exercise with HCM. Exercise doesn’t necessarily mean you have to get involved in competitive sports — your exercise plan can be tailored to your own preferences and abilities.

Although everyone with HCM will have different exercise programs based on their abilities and limitations, researchers have created some general guidelines for those with hypertrophic cardiomyopathy:

• Aerobic cardiovascular exercise should typically target 60 percent of heart rate reserve.
• Weight training should consist of light weights and high repetitions, and you should avoid heavy weights that put more strain on your system.
• Exercise should be performed at low to moderate intensity, not at high intensity.

3. Consider Your Environment

If you’re anxious about exercising with HCM, picking the right setting and conditions for exercise can give you peace of mind. It’s a good idea for people with any type of heart disease to avoid exercising in extreme temperatures, especially cold and windy weather.

People with HCM may have arrhythmia (irregular heart rate) that, in some cases, may lead to sudden cardiac arrest. Fortunately, a device called an automated external defibrillator (AED) allows others to administer lifesaving shocks to the heart if an emergency strikes.

Many public places have AEDs readily available and require staff to undergo training so they’re ready to jump into action if needed. Before joining a gym or other exercise facility, ask if they have a defibrillator and staff who know how to use it.

Some people with HCM have an implantable cardioverter defibrillator or permanent pacemaker to help control an irregular heart rhythm. If you have either, you may feel more comfortable informing the staff of your exercise facility about your condition. You can also wear a medical ID bracelet or keep a special card in your wallet that alerts others to your heart condition if you become unconscious or experience an adverse event.

Exercising with a partner, in group classes, or in places with other people around ensures you’re not alone if you need help. If you start noticing unusual symptoms while exercising, like shortness of breath, lightheadedness, or chest pain, you can take a break, knowing that others are around if you need assistance.

4. Track Your Starting Point and Goals

If you have HCM, it’s important to be mindful of your starting point when beginning a new exercise routine. If you’re new to exercise or haven’t worked out for a while, you’ll want to take it slow and pay attention to how you feel. It’s important to pace yourself when increasing the frequency, intensity, duration, or type of exercise. Keep a detailed log of the exercises you performed and your resulting heart rate changes so you can continually share it with your cardiology provider and ensure that your exercise plan is on the right track.

Be sure to attend regular checkup appointments and keep your doctor informed about any changes to your exercise plan. You may want to start with exercise supervised by a physical therapist. A stress test that monitors your heart rate during exercise will give your cardiologist a better idea of your current exercise capacity so you can observe changes over time.

Ultimately, the effects of exercise aren’t just good for your body. Physical activity can offer proven benefits to people with HCM, including reducing the risk factors for obesity and mental health issues. Choosing an active lifestyle (with some precautions as needed) will help you live life to the fullest with HCM.

Talk With Others Who Understand

MyHeartDiseaseTeam is the social network for people with heart disease and their loved ones. On MyHeartDiseaseTeam, more than 60,000 members come together to share stories with a community of people who understand life with hypertrophic cardiomyopathy and other types of heart disease.

How has hypertrophic cardiomyopathy affected your exercise training habits? Which low- or moderate-intensity exercise routines do you prefer? Share your experience in the comments below, or start a conversation by posting on your Activities page.