<span>Three benefits of exercise to the cardiovascular system are strengthening of the heart, improvement of the ability of the cardiovascular system to deliver oxygen to the muscles, and an increase in the number and size of mitochondria. Three benefits to the respiratory system are strengthening of the respiratory muscles, more surface areas to the lungs, and improves the ability of the blood to load and unload oxygen. Three benefits to the skeletal system are the bones become more dense, preventing osteoporosis, prevents bone loss in later years, and helps with good posture. Three benefits to the muscular system are improvement in strength, energy, and flexibility. </span>
The principles of specificity, progression, overload, adaptation, and reversibility are why practicing frequently and consistently are so important if you want to improve your performance.
In systole, you should expect that your mitral valve and tricuspid valve to be closed (snap shut) and you should expect your pulmonary valve and aortic valve to open. Hope this helps
