First and foremost, the body is formed and shaped by the consciousness. The self, as it forms and shapes the body, uses various tools such as diet and exercise.
The consciousness, in the first level of shaping, uses beliefs, expectations, thoughts, and emotions. The mental image of the self also plays a huge role in this.
Then the next level of shaping is done using hormones, diet, and exercise.
The trouble is that exercise, which is probably something like 5% effective factor in body shaping, is marketed to the mass society as being 95% effective. Look at all of the fitness gurus and physique models on IG, Youtube, etc. While occasionally throwing in the importance of the diet, they are constantly bombarding the minds of the people with the “You must kill it in the gym, by going hard every day.”
Why is that? Because they are sponsored by the supplement companies. Take this pre-work out in order to go hard. Take this to get the pump while lifting. Take this post-work out in order to recover. Take this, and this, and this supplement also along with your post-work out to recover. So that you can go hard as MF again. Take this protein shake to get your protein. Etc etc. It fucking goes on and on and on.
Forget these clowns.