system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to a body builder's muscles if he suddenly stops exercising?
gpt
As others have said, the muscles will atrophy. The SAID principle states that your body will adapt to the demands placed on it. For a body builder, that is the heavy weight lifting. If the person stops this, then the body will also adapt the other way, recycling the muscles so to speak for other things the body feels it should use the proteins for. This process can actually be measured 48 hours after a sharp drop in activity for a muscle, such as a casted limb. The process is gradual, but with the exception of losing innervation (sch as with paralysis) the lost muscle can be regained with work. 


If the diet was maintained, the body builder would also have a large caloric excess, resulting in adipose tissue(fat) being deposited on their body.