Does your heart get tired when running and/or during other types of exercise?
Posted March 26th, 2007 at 9:59 AM by Hariz Siddiqui
Section: Health & Fitness, Exercise
A healthy heart is so strong that it is almost never a cause of tiredness during exercise.
Tiredness during exercise comes from your muscles. They run out of fuel or out of oxygen. Skeletal muscles use both fat and sugar for energy.
When your muscles run out of their stored sugar supply, called glycogen, they cannot contract and function adequately. You feel tired, your muscles hurt and you have difficulty coordinating them.
On the other hand, your heart muscle gets energy directly from fat and sugar in your blood and even from a breakdown product of metabolism called lactic acid. It is virtually impossible for the heart muscle to run out of fuel unless you are starving to death.
A healthy heart doesn’t run out of oxygen either. Oxygen comes to the heart directly through arteries on its outside surface. If these arteries are not plugged up with plaques, they are large enough to supply all the oxygen that the heart can possibly need.
However, fatty plaques in arteries can block the flow of blood. When the heart does not get enough blood, it will hurt and can start to beat irregularly. Exercise won’t make a healthy heart hurt. If you develop heart pain during exercise, something is wrong and you need to check with a doctor immediately.
This post is written by Dr. Gabe Mirkin, M.D. and used with permission. Dr. Mirkin is board certified in Sports Medicine and has practiced for over 40 years. He has completed more than 40 marathons and was a talk show host of a nationally-syndicated radio program for about 25 years. For more articles by Dr. Mirkin, please check out: www.DrMirkin.com
***Note: We encourage EVERYONE to see a doctor before altering their diet, taking a supplement and/or performing athletic, fitness or other strenuous physical activity. It is your responsibility to evaluate the accuracy, completeness and usefulness of any information, instruction, opinion or advice contained in the content. Please also see our complete disclaimer.***
Tags: arteries, artery, blood, blood flow, contract, energy, fat, fuel, glycogen, heart, heart beat, heart muscle, heart pain, irregular heart beat, lactic acid, metabolism, muscle contraction, muscle function, oxygen, plaque, skeletal muscles, sugar, sugar supply, tired, tiredness
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