In the accrual of strength, each of the organism’s systems are augmented to elevate their performance so it is satisfactory in regard to the stress applied to it.
All of an organism responds to stress. This includes the endocrine system, muscle fibers, central nervous system, digestive system etc.
But there is a secret silver lining in terms to organism gains. It is like a pyramid. Minor changes are done as long as the body can get away with it.
But as more and more stress is encountered, more drastic measures must be made in terms of the organism’s self design and improvement.
Muscles can be improved for a while. Then the central nervous system needs to develop enough to fully use those muscles. The ligaments and tendons get their tensile strength upgraded next.
As long as there is a caloric surplus, all of these systems can be upgraded and maintained.
But in a caloric deficit bad things can happen.
First off protein is an antagonist of calcium. It drains your body of calcium.
Second, when in a caloric deficit the body is spread thin. It is already cutting corners where possible.
Thirdly in cutting, the protein intake has to be higher, so it compounds the calcium loss.
Fourthly, a person can be an ectomorph, which includes the feature of having small bones.
These factors all together form a perfect storm where bones can break.
Everyone has seen it happen to olympic lifters, their bones snap and nobody helps them.
This is because bone gains are the ultimate tissue remodeling achievement. Bones are the last component, the last resort, the last refuge to where the body can pull out it’s last ace card, against the enemy of stress.
In this desperate of times, truly the calcium deposits harden.
Good luck on not snapping bones in two. Usually the smaller ones break first, like a wishbone.