Aerobic exercise
Physical fitness
Exercise increases the heart rate, because the blood has to supply additional oxygen to the muscles.
Muscles during exercise need an adequate supply of glucose and oxygen. Heart rate increases during exercise to provide this supply.
The more you exercise - the more oxygen your body's muscles need. In order for your heart to supply more oxygen - it must beat faster.
Running is cardiovascular exercise, because it increases the rate at which the heart pumps blood through your body to supply your muscles with oxygen during their contractions.
oxygen
oxygen
The condition depend upon your regularity to do exercise They grow stronger and healthier if you do exercise daily but if you are irregular then whenever you do exercise lactic acid if produced in your muscles as the pryruvate change into lactic acid and a little energy due to less oxygen supply
The cardiovascular system (heart, lungs, and other big muscle groups) are strengthened during aerobic exercise through continuous, rhythmic movement. When you exercise, your muscles require more blood that is rich in oxygen, which causes your heart to pump more quickly to keep up.
Exercise has different effects on respiratory system. The moment you start exercising you may experience shortness of breath as a result of the oxygen debt created. This means that your muscles are using up more oxygen that the lungs can supply.
Exercise places greater oxygen demands on the body, therefore signaling the respiratory center to increase the rate of respiration in order to increase the oxygen supply to the body's muscles and other tissues.
Because the blood is diverted to the working muscles instead, as they need the more blood in order to provide oxygen for aerobic respiration