Johnny Manziel -- 'I'm Training Every Day' ... 'I'm In the Mountains' (VIDEO)

Johnny Manziel says he's like Rocky in "Rocky IV" when it comes to training -- climbing some insane mountains EVERY SINGLE DAY so he can get back in the league.

We got the QB leaving lunch at King's Fish House in Calabasas (no, it's not a nightclub) ... and asked with all of his partying, when does he make time to train?

"Every single day," Manziel told us ... before pointing to the mountain range and telling us he's been getting in work by climbing the hills.