This is definitely the kind of thing you should be working on. Do some searching for anatomy and drawing tutorials. Look up which books and resources are generally well-regarded, then practice from those. Draw from photos, draw from life, draw from studies by the Old Masters. Build a library of personal knowledge.

Keep in mind that muscle shapes can vary due to insertions and so on, but general structure always remains the same. Looking at different bodybuilders can help, as you'll see that while they're all shredded, their specific muscle shapes vary. Learn the structure of the skeleton, and how muscles attach and manipulate it. Learn how to reduce shapes to geometrical shapes for the sake of structure and perspective. And so on.

As harsh as my words are, please don't be discouraged. You have talent, and even if you didn't, this would be a worthwhile pursuit. So please don't feel bad or anything like that. I'm just trying to explain that this is a long journey and you have a lot to learn. Don't give up; art is very rewarding!