We should be in great expectation when we take on something to help us to become better, BUT, this question shows there is no real purpose or passion behind what you are doing.

This is a lot like saying how long will it take for me to become a world-class chef?

Some people study years and cook their whole life and never reach that status. The idea that body change takes a certain amount of time is just plain silly. It takes as long as it takes.  If you have a time set in your head, chances are you will be disappointed.

Instead ask: What's Next?

By asking what's next, you understand that this is a never ending journey that once you start does not end.  The question "what's next" means you have become engaged in the process and not the outcome. 

Once you start asking "what's next", you have realized this is a journey not a destination and are on your way to mastery.