What Is the Optimal Heart Rate for a Marathon?

The optimal heart rate while running depends, among other factors, on your goal and the race distance.

The longer we want to run, the lower the heart rate must be. The more intensely we want to push ourselves, the higher the heart rate must be.

In a marathon, our goal is to reach the highest possible heart rate at which we can maintain the pace and intensity over the full distance of 42.195 kilometers.

In general, during the final third of a marathon, heart rate increases anyway due to growing fatigue.

Heart Rate: The Relative Value Matters, Not the Absolute Number

Heart rate while running is always expressed as a percentage of maximum heart rate. This is because every person has a different maximum heart rate. Accordingly, each athlete has a different optimal heart rate for competition.

Older athletes, for example, reach a lower maximum heart rate than younger athletes.

This topic only becomes comparable when heart rate is expressed as a percentage of maximum heart rate. Once we know our maximum heart rate, we can calculate the optimal heart rate for a marathon, as well as for other race distances and for running training.

There are various methods to determine your individual maximum heart rate as accurately as possible.

This Is the Optimal Heart Rate for a Marathon

The optimal heart rate for a marathon is 85 to 90 percent of maximum heart rate, although runners in competition should orient themselves more toward the 85 to 88 percent range. Toward the end of the race, the value usually increases to 90 percent, and in the final kilometers possibly even slightly beyond that.

The Defensive Approach

Some guides even begin their recommendations at only 80 percent of maximum heart rate, meaning 80 to 85 percent. However, this would be a very defensive strategy. The risk of a performance drop is low in this case, but the chance of getting the maximum out of yourself is also very small.

The Heart Rate Strategy for the Marathon

It can absolutely make sense to start a marathon very cautiously, meaning in a range of 80 to 85 percent of maximum heart rate, and then slightly increase the pace in the second half of the race, known as a negative split. Combined with increasing fatigue, this will naturally lead to a rise in heart rate. Simply put, starting a marathon at 88 percent of maximum heart rate is often too aggressive and significantly increases the risk of a performance drop.

No Difference Between Professional and Recreational Runners

Whether you are a professional, a recreational runner, or a beginner makes no difference in the general recommendations. However, beginners are advised to choose the more defensive approach due to lack of experience.

Interestingly, women more often choose the defensive approach and are therefore less frequently affected by the so called hitting the wall phenomenon.

Is Heart Rate Constant During a Marathon?

No. Due to excitement, heart rate can even be elevated during the first few kilometers. After that, it usually stabilizes. Runners who take a defensive approach tend to stay slightly below their average value during the first half or first two thirds of the race, typically in the 80 to 85 percent range of maximum heart rate.

Toward the end of the race, heart rate increases slightly for almost all runners. This is caused by significant fatigue, fluid and energy loss, and the resulting increased effort and strain.

What Is the Best Heart Rate for a Half Marathon?

The value is only slightly higher than for a marathon. It is approximately 90 percent, or in the range between 87 percent and 90 percent, although here too the value approaches 90 percent toward the end, sometimes even reaching 91 to 92 percent.

Heart Rate for a 10 Kilometer Race

In a ten kilometer race or tempo run, a maximum heart rate well above 90 percent can be reached. Most athletes operate in the range of 90 to 94 percent of maximum heart rate. In some cases, even 95 percent.

Heart Rate in a 5 Kilometer Race

In a 5 kilometer race or a full effort over this distance, an average maximum heart rate of at least 92 percent should be targeted. Athletes typically operate in the range of 92 to 95 percent, sometimes even up to 97 percent.

How Can I Calculate My Heart Rate Zones?

We have developed a tool for this purpose.

You only need to enter your maximum heart rate, and the tool calculates all heart rate zones for different race distances as well as for the various training zones.

Summary: The Best Heart Rate for Running Races

• Marathon: 85 to 90 percent of maximum heart rate
• Half Marathon: 88 to 91 percent of maximum heart rate
• 10 Kilometers: 90 to 94 percent of maximum heart rate
• 5 Kilometers: 92 to 95 percent of maximum heart rate