Athletes often have a resting heart rate that’s around half that of a non-athlete, but why does this happen and is it good or bad? For budding athletes and current athletes who are thinking about heart health, understanding which symptoms are—and aren’t—a problem can guide potential lifestyle changes and requests for cardiac testing.
Why Athletes Have a Low Heart Rate
Put very simply, athletes have low resting heart rates because their hearts are stronger and more efficient. Just as exercise strengthens and enlarges your biceps and calf muscles, exercise strengthens your heart muscle and allows it to do more work with less effort.
When you participate in endurance training:
- Your body develops a greater density of capillaries inside the muscle.
- Your body increases the number and density of mitochondria (where fuel is converted into energy in the cells).
When you start getting close to your maximum heart rate with interval training, your body is forced to adapt and your heart muscle gets stronger. As your heart gets stronger, you can perform the same intensity of exercise without elevating your heart rate as much, allowing you to safely push toward even higher speeds, distances, and physical feats.
What Is a Normal Resting Heart Rate for an Athlete?
An athlete’s resting heart rate will often sit at around 30-50 beats per minute (bpm) whereas a normal resting heart rate is around 60-100 beats per minute. Resting heart rate is taken first thing in the morning or after sitting at rest for at least 10 minutes after physical activity.
The low heart rate often seen in athletes is accompanied by an increase in ejection or stroke volume. More blood is ejected from the heart with each pump, delivering more oxygen to the muscles in less time. As a result, fewer beats are needed to maintain a normal cardiac output and blood pressure.
Is a Low Resting Heart Rate a Problem?
If exercise training leads to a low heart rate but the person feels fine, there’s usually nothing to worry about. However, an athlete should see a doctor if he or she also experiences:
- Chest pain
- Shortness of breath
- Arrhythmias (an irregular heart rhythm)
Sometimes, heart pain while running can be caused by cramps in the intercostal muscles (the muscles between the ribs), lung issues, or even heartburn. However, if symptoms last for more than a few seconds, it’s best to get checked out.
Athletic Heart Syndrome
Endurance athletes sometimes develop a condition referred to as athletic heart syndrome. With this condition, the left ventricle of the heart becomes larger and thicker due to the athlete’s intense endurance training. The main symptoms, which aren’t always present, are extra beats or a heart murmur. There are no risks or ill side effects of having athletic heart syndrome.
It’s estimated that around 2% of athletes have athletic heart syndrome, so it’s relatively rare. However, it does share some similarities with hypertrophic cardiomyopathy, or enlarged heart, so if you have this condition, your doctor might still want to run some tests to rule out heart disease (which is a risk factor for sudden cardiac arrest and sudden cardiac death).
Diagnostic Testing for Athletes
Athletes who have cardiovascular symptoms or a family history of heart disease might be asked to undergo various diagnostic tests to see whether they have a heart abnormality or cardiovascular disease. The most common causes of sudden cardiac arrest (SCA) in athletes include congenital heart defects, especially hypertrophic cardiomyopathy. Knowing about these risks beforehand can help with exercise and career planning.
Over a period of a few weeks or months, a doctor might request:
- An electrocardiogram
- An echocardiogram
- Blood tests
- A stress test
- Other tests
In some cases, athletes can still play sports with a heart murmur or arrhythmia. In other cases, an athlete might be advised to choose an alternative career path. In the best-case scenario, any heart differences will be the result of increased cardiovascular fitness rather than heart disease, and the athlete can look forward to a long and healthy life.
What Is a Good Goal for Non-Athletes in Terms of Heart Rate?
If you’re an aspiring athlete or are just starting to develop an exercise routine, experts recommend aiming to keep your heart rate between 50% and 70% of maximum capacity when you train.
For an adult, your maximum heart rate is 220 bpm minus your age. So, a 20-year-old should aim to keep their heart rate between 100 and 140 bpm while exercising and a 40-year-old should aim for a heart rate between 90 and 126 bpm.
As your cardiovascular fitness improves, you can expect to see your resting heart rate decrease, enabling you to train longer and harder before you start to feel out of breath. According to a longitudinal study, even a 10% reduction in heart rate reduces your likelihood of dying from all causes by 16%. If you’re currently inactive, exercising regularly and maintaining a heart-healthy diet could also help you prevent or reverse heart disease and ideally prevent cardiac arrest.
It’s Still Best to Be Prepared
While physical activity is essential for a healthy heart, even otherwise healthy athletes can suffer sudden cardiac arrest. That’s why CPR training and AEDs are so important in any athletic environment. According to one study, 89% of young competitive athletes who suffered SCA in a two-year period survived the incident when treated with immediate chest compressions and the use of an on-site portable defibrillator.
If you run marathons or half-marathons, play competitive sports, or have known cardiac risk factors, it’s a good idea to have a user-friendly automated external defibrillator close by, like the Physio-Control LIFEPAK CR2 or Philips HeartStart FRx. If the worst were to occur and you went into cardiac arrest, a coach, bystander, or another athlete could use the device to save your life.
A Low Heart Rate in Athletes Is a Good Thing – But Testing Is Still a Good Idea
The lower heart rate of athletes is a result of greater cardiovascular fitness. However, there could still be a problem if the athlete experiences dizziness, weakness, fainting, arrhythmias, chest pain, or shortness of breath.
If you participate in endurance training and have cardiac symptoms or risk factors for cardiovascular disease, go ahead and make an appointment with your doctor. If everything looks fine, at least you’ll have ruled out any serious issues and will be able to continue your training with full peace of mind.