The Average Athlete's Heart Rate During A Marathon

The marathon dates back to 490 B.C. when an Athenian distance runner ran 26.2 miles from Marathon to Athens. Today, marathons are organized around the world allowing runners to run, or walk, the marathon distance of 26.2 miles. For the average runner, completing a marathon is a significant accomplishment and comes from your body making serious physiological adaptations to the conditions, including heart rate.

Intensity Range

For an average marathon runner, the heart rate during the race will range from 132 to 142 beats per minute. The heart rate will generally increase to 140 or more beats per minute during the first 30 to 60 minutes of the race and then slow down to a steady 135 beats per minute. These heart rate averages typically fall in the aerobic intensity zone based on percent of your maximum heart rate. The aerobic zone is 70 to 80 percent maximum heart rate and allows your body to transport oxygen to the working muscles during the marathon.

External Factors

Marathons can last from three to five hours with varying external and internal factors taking place throughout the race. For example, the environmental conditions at the start of the race could be calm and cool, but at the end of race could be above 70 degrees with 100 percent humidity. These external factors could cause the average heart rate to increase. Hydration levels throughout the race can also affect heart rate. As dehydration occurs during the marathon, the blood thickens, requiring the heart rate to increase in order to deliver enough oxygen to the working muscles.

Monitors

To track heart rate data during the marathon, runners can wear heart rate monitors equipped with a chest strap and wrist watch. The strap detects heart rate information and displays the data on the wrist watch. You can use the information to determine your intensity level during the marathon. For example, the excitement of the race, competitors and crowd may cause you to increase your pace that ultimately increases your heart rate beyond the aerobic intensity zone. Wearing a heart rate monitor can help you stay within the appropriate intensity zone and heart rate range.

Warning

According to the Journal of the American College of Cardiology, marathon runners have about 1 in 50,000 chance of suffering from a heart-related health issue, such as an acute heart attack, during the marathon. While this risk is small, you can take several steps during training, preparation and racing to further reduce your potential for heart-related issues. Follow a marathon-specific training program and utilize heart rate monitors during training to learn your individual training zones. Listen to your body during the marathon according to the varying environmental factors and stay properly hydrated throughout the race.