Many people use their heart rate as an indicator of their fitness level, and for good reason: this method is tried and true. Daily measurement of resting heart rate can help determine fitness levels as well as oncoming sickness and stress. What is is though about exercise that helps us to lower our heart rates? What exercise is best to achieve these optimal results?
For starters, let’s begin with the heart. The human heart is roughly the size of a fist and weighs anywhere from 10-12 ounces. Your heart has four chambers: two upper chambers called the atria and two lower chambers called the ventricles. All four chambers work in unison to help pump blood throughout your body and supply working muscles (during exercise) oxygenated blood.
The heart also consists of three distinct layers of the outer wall: the epicardium (outermost layer), the myocardium (the middle layer), and the endocardium (the innermost layer.) All three of these layers are a part of the pericardium. These layers contain the muscles that help the heart to contract muscle.
Your Heart Rate:
Heart rate, or pulse, is the number of times that your heart beats within a minute. Heart rate varies from each individual and can be a great gauge for knowing your heart-health, as according to the American Heart Society. Changes in heart rate can be a product of many factors.
These factors can include, but are not limited to:
- Underlying heart conditions
- Exercise adaptations
- Body position (resting, sitting, standing)
- Mental Stresses
Exercise and its Effects on Heart Rate:
In relation to heart rate adaptations, there are two forms of exercise that fall into this category: endurance and strength exercise. Endurance exercise is referring to activities that are of sustained duration and intensity that keep your heart rate elevated for maintained periods of time. This type of exercise elevates heart output and occurs in reduced blood vessel resistance. Examples of this would be: swimming, cycling, and/or running. Strength exercise involves short bursts of heart rate contractions. Strength exercise involves activities such as lifting. Usually most sports involve a combination of both strength and endurance.
In response to endurance training, the heart rate experiences changes in resting and submaximal bradycardia (slow heart rate), according to Dr. John Mandrola, a cardiac electrophysiologist practicing in Louisville, KY. These adaptations lead to increase in cardiac muscle and function, improved ventricular function, and an increase in resistance to restricted blood flow.
Another adaptation your heart experiences through endurance exercise is a predominant increase in left ventricle mass and thickness. As stated before your heart contains 4 chambers. The left ventricle is located in the bottom left portion of your heart below your left atrium. Your left ventricle is the thickest of your heart’s chambers and is responsible for pumping oxygenated blood to your body’s working tissues. With an increase in the the thickness of the ventricle, you are able to produce more forceful contractions, allowing your body to pump more oxygen rich blood to your body’s working muscles.
What does this all mean? To sum it up: the easier it is for you heart to pump blood, the lower your heart rate will be. With a slower heart rate, the left ventricle has more time to fill up with oxygenated blood to deliver the necessary nutrients to the body. Having stronger contractions to pump the same amount of blood throughout your entire body will eliminate the need to increase the heart rate. For the same outcome, you will have a reduction in the amount of beats per minute. According to Len Kravitz, a University of New Mexico professor, regular endurance exercise can result in a resting heart rate decrease of five to twenty-five beats per minute. This is why measuring your body’s resting heart rate daily is a good measure of increasing fitness. You can mark down data trends for your heart rate. Always remember that while you may see decreasing heart rate trend patterns, there may be some hiccups along the way. Heart rate, as discussed earlier, can be easily affected by environmental stresses, mental stresses, and even sickness.
Intensity and Duration:
In order to achieve a lower resting heart rate, it is recommended that you exercise at least 150 minutes in an aerobic zone. It is best to always consult with your physician prior to beginning an exercise program. When starting out, always increase steadily week by week.
Having a lower heart rate is not only a good measure of fitness, but also a step in the right direction towards having a healthy heart. If we are able to reduce the amount of beats per minute our heart works, think about the effects that would have on us in a day, month, or year! Endurance exercise can help us achieve these goals and understanding the physiology behind it can help us to learn more about the ways to improve our heart’s health!