The heart capacity is a measure of the amount of blood your heart pumps every minute. It is calculated using the following equation:
Heart Capacity = heart rate x stroke volume
Stroke volume is the amount of blood your heart pumps every time it beats. The capacity of the heart to pump enough blood every minute ensures all organs receive oxygen and essential nutrients.
For a normal individual who is resting, the heart pumps 5-6 liters of blood every minute.
How Does Exercise Affect Heart Capacity?
When exercising, your muscles rapidly use up oxygen. In order to keep up with demand, your heart pumps faster, and hence your heart rate increases. In order to keep up with demand, your heart pumps faster, and hence your heart rate increases. When your heart rate increases, your heart capacity or cardiac output increases.
Importance of Exercise for Heart Capacity
Exercising is considered important for the heart’s health. Here are some of the benefits of exercise for heart capacity.
Stronger Heart Muscles
Just like how exercise strengthens the rest of your body muscles, it strengthens the heart muscle too. A stronger heart pumps blood better.
Your Body Receives More Oxygen
With regular exercise, your body can receive/absorb oxygen from the blood better. This puts less strain on the heart when it pumps blood.
Improves Blood Flow Through Vessels
Studies show that with regular exercise, the blood vessels dilate to allow more blood flow.
Regulates Blood Pressure
Blood pressure is a very critical factor that talks about your heart’s health. By exercising, your blood pressure slowly drops down to normalcy without putting excess pressure on the heart’s pumping capacity.
Reduced Resting Heart Rate (RHR)
An increase in your Resting Heart Rate (RHR) is associated with increased mortality. Exercise helps bring down the resting heart rate. The RHR for athletes can be as low as 40 bpm.
The Influence Of Genetics On Heart Capacity
CREB1 Gene and Heart Capacity
The CREB1 gene encodes the CAMP Responsive Element Binding Protein 1, which plays an important role in several biological pathways. Variations in the gene are proven to cause various diseases, including memory disorders and Huntington’s disease.
The rs2253206 SNP in this gene causes changes in heart rate while exercising. The AA genotype causes heart rate improvements because of exercises. The AG and GG genotypes show no such positive relation.
Non-genetic Influences On Heart Capacity
Just like how exercise changes your heart capacity, other non-genetic factors increase or decrease your heart’s ability to pump blood.
Hormones - Certain hormones affect the contraction of the heart and hence affect stroke volume.
Stress - Norepinephrine is a chemical released in the body when you are stressed. This chemical right away increases heart rate, which in turn increases heart capacity. Epinephrine is another chemical the body produces when the person experiences fear or anger. This also increases the heart rate and pumping capacity.
Changes in body temperature - Increased body temperature can cause increased heart rate and heart capacity
Sex - Women have a higher heart rate than men, and hence their heart pumps blood faster.
Age - The heart rate and capacity to pump blood is the fastest at birth and reduces slowly as people age.
What Happens When Your Heart Capacity Is Higher Than Normal?
It is quite normal for the heart capacity to increase during exercise and other external factors. However, when the heart capacity or cardiac output is consistently high, it can lead to pulmonary edema (fluid accumulation in the lungs). This can be a life-threatening condition.
If exercising causes abnormal increases in heart rate and heart capacity, you may have to slow down the intensity of working out and give the body adequate resting time to stabilize.
What Happens When Your Heart Capacity Is Lower Than Normal?
When the heart capacity is lower than normal, it gets difficult for the other parts of the body to receive oxygen. For maintaining your heart’s pumping capacity, the heartbeat increases to pump more blood with every passing minute.
The adrenaline glands release adrenaline that reaches the heart and pushes it to beat faster. Consistently lowered capacity and higher heart rate can weaken the heart muscles with time.
Recommendations To Improve Heart Capacity With Exercise
Start slow
Exercise definitely helps your heart capacity improve. However, start slow and let the heart get used to all the physical exertion. As your capacity improves, you can start training intensively.
Listen to your heart
Does exercising leave you tired, breathless, or dizzy? Get the core problem checked before you continue to exercise. If you are genetically designed to experience high blood pressure or abnormally high heart rate because of exercise, you could feel worse after a workout session.
Moderation is the key
A healthy individual who is not trained by a professional should consider moderate exercises over high-intensive training.
Improve your recovery heart rate after exercise
Aim to improve your heart rate recovery after exercise. Follow a mix of light, moderate, and intense exercises to get your heartbeat to normalcy quickly.
Summary
- The heart capacity is the amount of blood the heart can pump every minute. Heart capacity is measured as heart rate X stroke volume.
- When you exercise, your heart rate increases, and hence your heart capacity increases too.
- Exercising brings down blood pressure levels, keeps you fit, strengthens your heart muscles, and reduces Resting Heart Rate (RHR)
- Certain variations in the CREB1 gene can significantly improve heart rates because of exercise. Variations in the CHRM2 gene cause increased risks for lowered heart rate recovery after exercise.
- Non-genetic factors like age, sex, stress, and hormones also decide how much blood your heart can pump during and after exercising.
- Moderate exercises give the body time to recover and improve your heart recovery rate.
References
https://wa.kaiserpermanente.org/healthAndWellness?item
https://medicalxpress.com/news/2018-09-genes-heart.html
https://www.health.harvard.edu/heart-health/what-your-heart-rate-is-telling-you
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6529381/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2575587/
https://www.medpagetoday.com/blogs/skeptical-cardiologist/83528
https://www.uofmhealth.org/health-library/tx4080abc
https://www.theonlinelearningcenter.com/assets/carter/46/course_01/module_04/mod_04.pdf
