How Does Muscle Size Influence Lifting Capacity?

[Goldenwind]

Homework Statement

This isn't homework, just something I'm wondering.
Using the theories and links between Work and Energy, why is a larger muscle able to lift more (and/or find it easier to lift the same mass) than a smaller one?

Homework Equations

W = Fd
W = E_f - E_0
KE = (1/2)mv^2
PE = mgh

 

[HallsofIvy]

A larger muscle can apply more force and so, since, W= fd, do more work. It takes exactly the same force and energy to lift a given object, whether the muscle is larger or not. It is just that the stronger (larger) muscle can apply more force. That's pretty much what "stronger" means!

It is also true that a longer arm might have more mechanical advantage and so be able to lift an object while applying less force (but using the same energy) but that is a matter of bone length, not muscle size or strength.

 

[Moetasim]

The larger muscle has a greater cross-sectional area and thus a larger number of muscle fibers. These muscle fibers are responsible for generating the force needed to lift an object. When a muscle contracts, it uses energy stored in the form of ATP (adenosine triphosphate) to produce force. This force is then transferred to the object being lifted through the tendons.

According to the work-energy theorem, the work done on an object is equal to the change in its energy. In this case, the work done by the muscle is equal to the change in kinetic energy of the object being lifted. Since the larger muscle has a greater number of muscle fibers, it is able to produce a greater force and thus do more work on the object.

Additionally, the larger muscle also has a greater capacity for storing and utilizing ATP, which means it can sustain its contraction for a longer period of time. This allows the muscle to lift heavier objects or lift the same object for a longer duration without getting fatigued.

Moreover, larger muscles also have a greater potential for storing potential energy in the form of glycogen. This energy can be converted into ATP during exercise, providing the muscle with a continuous supply of energy to sustain its contraction.

In summary, the larger muscle is able to lift more or find it easier to lift the same mass because it has a greater number of muscle fibers, a larger capacity for storing ATP and glycogen, and a greater ability to sustain its contraction.