11/18/2024
I did some more research on muscle fibers and found something very interesting.
Muscle fibers are about half the diameter of a human hair, which is why it takes about 20-50,000 fibers to make up each major muscle.
While muscles can be strong, single muscle fibers themselves are very fragile.
MPa is a measure of tensile or tear strength. Muscle fibers have an MPa of .44--less than half of 1 MPa.
A human hair has an MPa of 260.
Which means a single muscle fiber is 590 times weaker than a human hair.
If human hair was as fragile as a muscle fiber, just combing your hair would tear it all into pieces.
This is why baseball players and other athletes should not be lifting heavy weights and why weights tear muscle fibers. The individual muscle fibers are very weak and easily torn.
While the body does repair the torn fibers and they do become bigger and stronger, the body also creates scar tissue that gradually accumulates with each lifting session, making the athlete stiffer, slower and more easily injured. A good example is Aaron Judge, who has seen his sprint speed ranking drop from #145 to #389 (a drop of 244 places) over the past 6 years.
Light to moderate resistance is a better way to increase strength. Tom Brady did this by replacing weights with bands, was able to maintain his flexibility and had one of his best years when he retired from football at age 45.
