I have read up to somewhere in the chapter 400 range a few years ago, but I only realised recently that the manga is still ongoing. So I thought, why not pick it up and marathon it up to where it is right now.
As I am writing the article I've already read about the first 20 chapters. To be totally truthful, the manga is what is inspiring me to start boxing. From next week onwards I will also be joining a boxing gym, I'm sure it won't be exactly the same as in the manga. And I don't know how good I will be at boxing, but when you like something it's worth giving it a shot because you never know.
Hajime no Ippo probably the longest running manga, it has over 950 chapters in it. It is about Ippo who wants to become a boxer and the hardships he faces as he achieves his goals in boxing.
There is an anime about it too. Oh and in english it is called Fighting Spirit. So check it out!