Why Your Heart Rate Gets So High When Running

Have you ever found yourself wondering why your heart rate gets so high every time you run? Five minutes into your run and your HR is already 180+? You start wondering if you’re going to die… or if something is wrong with you.

Hopefully this post will give you some clarity on why your HR is so high and what you can do to lower it.

You’re working, so it’s natural for your heart rate to increase. The reason it gets so high is because you’re working hard—maybe too hard, especially if every run is hitting 180+.

As effort increases during running, so does your muscles’ need for oxygen. This is one of the reasons your heart rate rises. Your heart has to work harder to deliver the oxygen needed to support the effort and intensity you’re running at. Additionally, your body produces waste products during exercise that the cardiovascular system has to help clear.

The harder you work = the more oxygen your muscles need and the more waste products produced = higher heart rate.

So if you want your heart rate to be lower while running, you need to decrease your effort. This is why a lot of runners and coaches talk about “easy runs.”

Easy runs are done at an easy effort, typically around 60–75% of your max heart rate. Running at this pace helps build your aerobic engine, if you will.

One of the key adaptations that lowers your heart rate is an increase in stroke volume. Stroke volume is the amount of blood your heart pumps with each beat. The more blood your heart can pump per beat, the fewer beats it needs to deliver the same amount of oxygen.

These light-to-moderate efforts help the heart adapt by making the chambers larger and the heart muscle stronger, allowing it to pump more blood per beat.

Harder efforts, like Zone 4 and Zone 5 (90–100% HR), stress the heart and force it to adapt so you can handle more work at that intensity. This type of training improves VO₂ max (your body’s ability to use oxygen) and further improves stroke volume.

Doing this intensity is important for performance improvement. However, the risk of doing all your runs at this effort is that you’ll need multiple days to recover, and it often leads to injury, overtraining, or chronic fatigue.

This is why many coaches recommend the 80/20 rule:

80% of runs: easy to moderate effort 20% of runs: harder efforts

This approach builds your aerobic engine while also challenging your cardiovascular system to adapt and improve (and it trains your anaerobic system as well).

There are also other reasons your heart rate could be elevated, such as dehydration, environmental conditions (especially heat), or inaccurate heart rate monitors. While we won’t go deep into those factors today, they should still be considered.

This is why many coaches (myself included) like to use RPE during runs. RPE stands for Rating of Perceived Exertion.

Most runs should feel like a 2–3 out of 10 effort (with 1 being the easiest and 10 being the hardest). A good way to check if your effort is easy is the talk test. You should be able to carry on a conversation while running. If you can only say a few words and find yourself gasping for air, you’re going too hard.

For new runners, you may need to use the run/walk method. Run until your heart rate starts to climb, then walk and let it come back down. Then start running again and repeat this for the duration of the workout.

This may be what it takes at first to keep your runs truly “easy”—and that’s okay. Most runners start here.

Just stay consistent, keep showing up, and you’ll start to see improvements in your heart rate at different effort levels.

The Takeaway

If your heart rate is always high when running, you’re likely running every run too hard.

Incorporate the 80/20 rule, and don’t be afraid to use the run/walk method if needed.

Keep showing up, stay consistent, and the improvement will come.

“Rome wasn’t built in a day, but it was worked on every day.” — Roy Williams

If you’re looking for a structured, personalized training program, I offer 1:1 coaching and would love to help. I also offer standard training plans for runners who may not want full coaching or aren’t ready for that investment yet.

Check out the links below.

https://www.camiamendurancecoaching.com

https://www.trainingpeaks.com/my-training-plans/12-week-beginner-plan