Leveling Up My Isekai'd Abs 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

Sung Suwoo has it all – he’s handsome, strong, and popular. His only problem is he can’t grow abs no matter how much he trains! After being dumped by his girlfriend for having a flabby tummy, he gets isekai’d into a webcomic universe! Can he successfully return if his only ticket back home is by becoming the hottest male character of the romance genre with S-rank abs?