Genius Martial Arts Trainer is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

[By the Studio that brought you and and ] during the great pandemic, my gym went under. While desperately trying to make ends meet, I possessed a character in Murim. I was excited to see that I was in the Shaolin Temple, but what the hell? Everyone’s bodies are wrecked from working out the wrong way! How can I just sit back and watch when I used to be a personal trainer?! I’ll teach you the correct, modern exercise methods and heal you all with low-frequency treatment and infrared therapy using inner energy! D-? until opening Shaolin gym.