The term “large heart” is used figuratively to denote someone who’s kind and very welcoming to most people. While a lot sportsmen and women have “large hearts” figuratively, as know most of them to be philanthropists, they also have “large hearts” literally. The size of a person’s heart is approximately the same size as their clenched fist.

Like when you make a fist in an attempt to throw a punch, what ever you see is approximately the size of your heart, except you’re sportsman which means your heart is larger than the size of your clenched fist.

This is a consequence of adaption, endurance training which all sportsmen go throw requires vigorous and effective pumping of blood by the heart and as the heart is made of muscular tissue, the vigorous and continuous pumping of large volume of blood during training makes the heart walls larger and stronger and more effective in carrying out it’s function.

Just think of an olympic weight lifter who trains hard to be able to lift heavier weights. In the long run he will end up being larger, bigger and more muscular, that’s what happens to the heart. It’s called adaption.