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Can my heart rate be too high when running (or cycling)?

Published 4 November 2020. Written by Chris Worfolk.

Can my heart rate be too high while running? It is possible but is often nothing to worry about. In this article, I will explore what a safe heart rate is, how to calculate it and why some low heart rate training may also be beneficial.

Everything in this article also applies to cycling. I have written it from the perspective of a runner, but it equally applies to being on the bike.

Maximum heart rate

Your maximum heart rate is individual to you. As a rough calculation, we can use the formula:

220 - your age

For example, a 40-year old would typically have a maximum heart rate of 180. Like BMI, this is a pretty rough estimate but one that is useful.

But don't worry if it exceeds this. These are averages and most people find that their maximum HR is 10-20 beats either side of this number.

So, if a 40-year-old was clocking a max HR of 200 on a really hard run, that would not be cause for concern¹. However, if the same 40-year-old was clocking up 230, that would be worth speaking to their doctor about to see if there was anything else going on.

Working at a high heart rare is generally safe, not least because if it gets too high, your body will will force you to slow down².

What risk factors are there?

The problem with a very high heart rate is that it works the heart extra hard and increases blood pressure: the faster the heart pumps blood around the body the more pressure there is on the arteries. In short, we are worried about you having a heart attack.

Therefore, if you have any history coronary disease, it may be that a safe heart rate for you to exercise at would be lower than an individual with no history of heart disease. In such cases, speak to your doctor about what a safe heart rate to work out at might be for you.

While all of this sounds scary, remember that exercise ultimately strengthens your cardiovascular system and makes you healthier.

What about warning signs?

Running is often uncomfortable and those new to running (or even some of us seasoned veterans) sometimes struggle to distinguish between "good pain" when we are working hard and pushing our bodies and "bad pain" when we are doing ourselves serious damage.

You are likely to experience uncomfortable sensations around your chest and lungs as your body tries to keep up with the muscles' demand for oxygen.

But if you are experiencing intense pain in your chest, this could be something more serious. Or it could be nothing.

Causes include being new to running, muscles cramping in your chest, heartburn, asthma and finally something more serious. There is a good round-up by Women's Health (and our hearts work the same way, so it is applicable to all genders).

Are your numbers accurate?

One thing to watch out for is the way you measure your heart rate.

The most accurate way is using a chest strap. This will give you the most accurate numbers that you can base these calculations on.

If you have a wrist based HR monitor in your watch, it is still fairly accurate. Especially over a long period of time such as a 30-minute run. It should do a great job of recording your average HR.

Watches are less accurate when it comes to spikes, though. For example, if you are doing plyometrics at the gym, they may struggle to capture the quick rises and falls of your HR. And potentially, if you are finishing your run on a big sprint finish, it may not be 100% accurate in capturing that max HR.

How do I lower my HR?

Run more. As you improve your cardiovascular system, your heart will be able to deliver oxygen more efficiently and with a bigger stroke volume, so will not need to beat as fast.

This will not reduce your maximum HR. Instead, it will mean you can run faster at your max. But it also means that running at the same speed you used to run can be done at a lower HR.

What type of running should you do?

Any. The body does not have just one limiting factor and so if you want to improve your speed and get stronger, working out at a range of intensities improve all of your bodily systems. The fastest way to get faster is with one long run, one fast run and one interval session per week.

But that can be quite intense. Another option is to follow the 80/20 rule. Make 80% of your running easy (if running ever feels "easy") and 20% hard.

It is important to note that running at lower intensities will help you improve. You do not have to be working hard all of the time to be getting the best results.

Low heart rate training, defined as keeping your heart rate below 70% of your max HR, is popular with some athletes because they can do a tonne of it without requiring a lot of recovery time.

But be aware that it can also be annoying: unless you are a naturally speedy runner, you may find you have to run/walk a lot of the time to keep your heart rate this low.

Summary

Heart rate is an individual thing. Some people's beat faster and others beat slower. It is difficult to make direct comparisons between different people because genetic and environmental factors work alongside fitness level and intensity of exercise.

Unless you have any risk factors, it is generally safe to work at an intense level. Exercise strengthens our cardiovascular system, so it is not something we should be afraid of.

However, you do not need to be working at an intense level to improve your running. Working at lower intensities most of the time will keep to keep you injury and illness free while still improving your fitness.

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