Why does your heart beat faster when you exercise

Exercise is an important part of disease prevention – and that includes cancer prevention, too. But not all exercise is created equal. It’s essential that some of your exercise make your heart beat faster than it does when you’re resting.

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Speedy Delivery System
Beating the Heat
The Cardiovascular Drift
All Systems Go

Getting your heart to beat faster trains your body to move oxygen and blood to your muscles more efficiently, helps you burn more calories and lowers your cholesterol. All of this can help you stay healthy and lower your cancer risk.

According to the American Institute for Cancer Research, 150 minutes of moderate physical activity or 75 minutes of vigorous exercise each week can help lower your cancer risk. It’s the vigorous exercises that can help you get your heart rate up.

How to measure your heart rate

So, how do you determine your heart rate? One of the easiest ways to measure your heart rate is with a monitor, says Whittney Thoman, exercise physiologist at MD Anderson’s Cancer Prevention Center. This is typically a watch or a strap that goes around your arm or chest that syncs with a watch or another device. Many wearable fitness trackers now include heart rate monitors.

If you don’t have a heart rate monitor you can check your heart rate using your pulse. To find your pulse, use two fingers (your middle and your index fingers) to find your carotid artery, just below your esophagus or throat. Then, count the beats you feel for 10 seconds. Multiply that number by six. That’s roughly the number your heart beats per minute.

Understanding your heart rate

Now that you know how to measure your heart rate, you can determine:

Active heart rate: how fast your heart beats when you’re active or exercising
Resting heart rate: how fast your heart beats when you’re resting or relaxing
Maximum heart rate: the highest rate your heart can obtain during activity. To find your maximum heart rate, subtract your age from 220. For example, if you’re 40 years old, subtract 40 from 220 to get a maximum heart rate of 175. This is the maximum number of beats your heart is capable of per minute, but you should not try to exercise to this level.

Check your pulse or your heart rate monitor while you’re resting and then again while you’re exercising to compare your resting heart rate to your active heart rate.

If you’re working at 50 to 70% of your maximum heart rate, then that exercise is considered moderate. If you’re working at 70 to 85% of your heart rate then its vigorous exercise. If your heart is working harder than that (above 85%) it could be dangerous, so be sure to back off or consult your doctor.

If you’re worried about an increased heart rate causing other health problems or have had heart problems in the past, talk to your doctor before you begin exercising at a higher intensity.

Ways to get your heart rate up

Now that you know how to determine your heart rate, the next step is to find exercises that will help boost it to improve your health. Here are a few ways to get your heart rate up.

Set an incline. If you’re on the treadmill increase the incline. Or if you’re walking outside look for hills. This will challenge your muscles and help increase your heart rate.
Take the stairs. Just like adding an incline, stairs bring a new challenge to your workout.
Alter your pace. Whether you’re walking, riding a bike, swimming or practicing yoga, you don’t have to increase your pace for the entire workout. Add in short bursts of increased effort at a faster pace. Over time, you’ll be able to increase the duration of these bursts.
Take shorter breaks. If you’re doing an interval workout or lifting weights, take shorter breaks in between the different exercises.

When we workout, we typically think about muscles in our arms, legs, back or abdomen. However, these aren’t the only muscles that get stronger with regular exercise.

Your heart, which is a muscular organ, gets a workout during exercise, too. Your heart’s full-time job is to distribute blood throughout your entire body. When it beats harder and faster, it can grow stronger and more resilient.

When you’re stationary, your heart should beat between 50 to 100 times per minute to fall within the normal range. To narrow this down a little, most people’s hearts beat between 60 to 80 times per minute.

When you start your exercise, your muscles will start to work harder and demand more oxygen. This demand will cause sympathetic nerves to stimulate the heart to beat faster and with more force to increase overall blood flow. The sympathetic nerves will also stimulate the veins, causing them to compress. These narrower veins will increase the velocity at which blood flows through your body. This will ultimately increase the amount of blood returning to the heart.

How fast your heart pumps during exercise depends on numerous factors such as:

Your age
Your fitness level
Intensity of the workout
Your heart’s overall strength

Cardiac output is the rate of blood pumped by the heart. You can calculate this output by multiplying the rate at which the heart beats (heart rate) by the volume of blood the heart ejects with each beat (stroke volume). When your heart is pumping at full force, the cardiac output is about 20-25 liters per minute —compared to 5 liters a minute for a heart at rest.

Once you are done with your exercise, your heart rate will begin to slow to a normal pace.

Since your heart is a muscle, it can benefit from being “strained” to a certain degree which trains and prepares it to work harder when you need it to, but it also helps it to perform better – even while at rest. Frequent exercise will cause your heart to grow stronger, making it easier for it to distribute blood throughout your body. A stronger heart means that each time your heart beats, it pumps more and more blood throughout you body. This allows your heart to beat less, while still distributing the same amount of blood. All of this can keep your blood pressure under control.

Keep your heart healthy with regular check-ups by your doctor. Don’t have a doctor? Find one here.

Exercising at a steady pace for a prolonged period will cause your heart rate to increase.

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Your heart rate increases when you begin to exercise, then plateaus off and remains elevated for a prolonged period as long as you maintain the same pace.

If you increase your effort, it will go even higher until you reach your maximal capacity or target heart rate. Calculate that figure by subtracting your age from 220 advises Mayo Clinic. A middle-of-the-road rate at which your heart should beat during exercise is 50 to 70 percent of your maximum heart rate.

The quick responsiveness of your heart to exercise is due to the demand for oxygen in your muscles.

Your heart beats faster during exercise because it needs to send oxygen to your muscles.

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In order to continually produce energy for contraction, your muscles need oxygen. Oxygen is carried on your red blood cells from your lungs and travels to your heart to be pumped to your working muscles. Inside the muscle cells, tiny organelles called mitochondria combine oxygen with glucose and fat to make ATP, the basic energy molecule. When you increase your muscle action, your heart beats faster and harder to send oxygen to your cells, ejecting a greater volume of blood with each stroke.

Beating the Heat

High environmental temperatures during exercise can increases your heart rate above normal levels because your heart has to send blood to your skin to cool you down while continuing to supply blood to your working muscles. These two demands force your heart to beat faster says Mayo Clinic. The more you train in a hot environment, the more efficient you become at cooling your body while satisfying the energy demands of your muscles.

The Cardiovascular Drift

During long-duration exercise, your heart rate may gradually increase, even if you maintain a set pace. This "cardiovascular drift" occurs as you lose water through sweating and as your heart directs more blood to your skin in order to cool you down. Your heart rate will increase because blood is being diverted from your working muscles, and therefore, it has to pump more often to keep your muscles supplied with oxygen and energy.

Cardiovascular drift occurs regardless of whether you are staying hydrated. But according to researchers at the University of Utah, your heart rate will increase even more if you are getting dehydrated. Your body temperature will also rise with dehydration, leading again, to an increased heart rate during prolonged exercise.

All Systems Go

All your body's systems depend on oxygen, and your heart must continue to feed all your tissues while you exercise. Many other things affect heart rate during exercise, including your emotional state, how much food you've eaten prior to exercise, your body position and whether the exercise is continuous or characterized by periodic bursts.

With regular training, your heart becomes stronger and pumps a greater volume of blood with less effort, lowering your heart rate at rest and during exercise. Your muscle cells grow more mitochondria and become more efficient at extracting and using oxygen, decreasing demand during exercise.