THE EFFECTS OF EXERCISE ON PULSE RATE

The Effects of Exercise on Pulse Rate

The Effects of Exercise on Pulse Rate

Introduction

During each heartbeat, the muscles of the heart contract causing a wave of pressure which forces blood through the arteries. This wave of pressure is known as a pulse. There is one pulsation for each heartbeat. The pulse can be felt at various points on the body where the arteries are just under the skin, such as the temples, neck, crook of the elbow, wrist, groin, back of the knee, and the inside back of the ankle. The normal pulse rate varies with age. Below is a chart listing the range of heart rates and average heart rate for various ages. With exercise or physical activity, the heart rate increases to supply the muscles with more oxygen to produce extra energy. The heart can beat up to 200 times per minute with extreme exercise. The brain sends nerve signals to the heart to control the rate. The body also produces chemical hormones, such as adrenaline, which can change the heart rate. When we are excited, scared, or anxious our heart gets a signal to beat faster. During a fever, the heart beats faster to bring more blood to the surface of the body to release heat and cool the body. The heart rate increases during and after a meal to send more blood to the digestive system. A trained athlete's heart can pump more blood with each beat so his or her heart rate is slower. Likewise, an athlete's recovery time is shorter.

There are two ways the heart can meet the body's need for oxygen during exercise. It can beat faster or it can beat harder, moving more blood per pump. But it can only beat harder if it has been strengthened through regular exercise.

Discussion

Physiology of Heart

Every heartbeat triggers a sequence of events called cardiac cycles, which consists mainly of three stages: atrial systole, ventricular systole and diastole. The cardiac cycle causes the heart to alternate between contraction and relaxation about 75 times per minute, i.e. the cardiac cycle lasts about 0.8 second. During atrial systole, it contracts and projects aurículaaurículas blood into the ventricles. Once the blood has been expelled from the atria, the atrioventricular valves between the atria and ventricles close. This prevents the backflow of blood into the atria. The closing of these valves produce the familiar sound of a heartbeat. The ventricular systole involves the contraction of the ventricles ejecting blood into the circulatory system. Once the blood is ejected, the two semilunar valves, the pulmonary valve on the right and left aortic valve is closed.

Finally, the diastole continues the relaxation of all parts of the heart to allow the arrival of new blood. The expulsion of the blood causes rhythmic pulse that can be felt in the arteries: radial artery, carotid artery, and femoral artery, etc. Looking at the time of contraction and relaxation you will find that the atria are at rest apr ...