I would say that it's obvious to anyone that works out or is familiar with athletics. But take someone who may not be well versed in this space and it's easy to fool someone

In high school, I spent most of my spare time riding my bike. My pants were a size or two too big in the waist so my legs would fit in.

I was great at leg press, but I could barely bench the bar. Rock climbing isn't my sport, and I swim like a brick.

It’s more that the human body is very good at shedding the non required. The result is the same, but the logic is different, human physiology will actively and quickly cannibalise under-utilised muscle mass as muscle mass is expensive.