Roper
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The heart serves only one purpose in the human body – to move blood through the circulatory system. While blood has several different functions, its most important function is to deliver oxygen to all the cells of the body. The body’s cells cannot function without a constant supply of oxygen. The more work we do, and the harder we push the body, the more oxygen we need.
When the body detects that we need higher amounts of oxygen, several autonomic effects take place. The heart rate increases so that blood is pumped through our system more quickly. The faster the blood courses through our veins and arteries, the more oxygen can be delivered.
As our heart rate increases, we also begin to breathe faster and more deeply. The faster our blood flows, the more oxygen it needs to replace the oxygen that is expended. So, our breathing increases to match the flow of our blood.
If too much exercise is done too fast, the heart cannot match the oxygen demands of the body. When oxygen demands are too great, a person will usually voluntarily stop the exercise to allow the body to catch up. If a person doesn’t stop, they will pass out. In most cases, your body will not allow you to kill yourself through exercising. If you already have a weak heart, it is possible that exercise could lead to heart failure.
Health experts and trainers often talk about a target heart rate. This is the theoretical maximum that your heart and breathing work together healthily to sustain your activity. The target rate is about 65 to 85 percent of maximum intensity. Regular adults have a resting heart rate of 60 to 90 beats per minute. During exercise, it can increase to as high as 165 bpm.
 Posted 5367 day ago
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