Well, fitness raws manhwa usually showcase diverse workout routines and training methods. The characters might face setbacks and achievements, making the plot exciting. Also, the art might highlight the progress of the characters' physiques over time.
The best place to look for the ennead manhwa raws is on official manga sites or authorized distributors. However, if those don't have it, you could explore some lesser-known manga aggregator sites, but always be cautious about the legality and potential risks.