Jake Gyllenhaal has a ''tendency to cry on planes''.

The 'Nightcrawler' actor revealed he sobbed on a jet while reading the script of his latest boxing blockbuster 'Southpaw', but confessed it wasn't a rare occurrence for him as he often gets weepy while flying.

He said: ''I sat there reading the script and it made me cry when I read it. There were two or three times in the script when I was reading it, where I was just crying. And even when I read other drafts as they did rewrites on the script, I remember I was in a plane and I was reading it in a plane, and I just started to cry and cry, and everybody looked at me. I have a tendency to cry on planes in general no matter what's happening, I don't know what it is. I think it's the altitude.''

The 34-year-old hunk admitted there was nothing he could do to conceal his emotional state from his fellow passengers, but attempted to hide his tears with a towel.

He continued: ''I was covering myself with a towel, I was trying everything I could, but it was just so good, the script.''

Jake believes his tears were worth the trouble though, as even when he was reading through the plot he thought it would be the ''perfect'' film for him to do.

Explaining how he came to appear in the movie, he told BBC Radio 1 DJ Nick Grimshaw: ''Somebody sent it [the script] to me, and they said, 'You know, Antoine Fuqua who directed 'Training Day' and 'The Equalizer' is directing this movie, and he's a big fan of boxing. He's been boxing all of his life and he wants to make this movie and it's really important to him'. And I read the script, thinking about how Antoine's made movies with his vision, and I just thought, 'Wow, it'd be perfect to do it,' and then he asked me to do it and that was that.''