Jake Gyllenhaal ''fell in love with boxing'' on the set of 'Southpaw'.

The 34-year-old actor trained as a pugilist for months to play Billy Hope in the new movie because he didn't use a stunt double for his fight scenes.

Since shooting wrapped on the drama, Jake has continued to step into the ring to box and has the utmost respect for the sport and fighters who compete all over the world.

He said: ''I'll go to the boxing gym and I'll get bummed when I learn something new. I think, 'Awe, I could have put that in the movie!' I fell in love with boxing.''

Jake admits he was nervous about getting in the ring for the first time because he didn't want to be ''the actor who's just trying to protect himself.''

He explained to Us Weekly magazine: ''When [director] Antoine (Fuqua) told me he was going to shoot it like real HBO/Showtime fights - that we weren't going to be pulling any punches, so to speak, I thought, 'Well, there's no real way to cheat here.' That's one of the great things about my job, I got to learn a new skill that I never would have and learn about a world I never would have.

''I didn't have a stunt double. By the time we started shooting, I had sparred enough - I mean, it was different (in practice) when I was wearing protection. But I remember, as soon as the real guys were there - we had real referees in the ring, real HBO fight cameramen - you don't want to be 'the actor' who's just trying to protect himself. If you get hurt, you get hurt.''

Jake also stars in the acclaimed film with Rachel McAdams, 50 Cent, Forest Whitaker and Naomie Harris.