What Happens When I Stretch?
What happens is simply this. When you stretch your arms and legs, you squeeze the arteries and veins which are a part of your arms and legs, much as happens when you pull on a piece of rubber tubing. The tubing becomes flat instead of perfectly round, and it is not so easy to send water through a flat tube as through a round one. Just so with the heart. It is the heart’s business to send blood through the arteries at all times, and when you make them flat the heart’s job becomes just a little harder, and it goes to work beating just a little faster to overcome this extra difficulty. By that time you are through stretching and the heart is busy pumping blood a little faster than ordinarily, and that is what makes you feel so good after you have stretched.