I think the best training is when Capt. Bernard gives you a mission to wipe out a certain bandit camp. If you can manage to do this, then be sure to collect the bandit leader’s spurs and take them back to Capt B. At this point you’ll get options in the talk menu to train with practice and real weapons. Pick practice weapons. You’ll get in the ring with wooden swords, shields, axes, maces, or what.
Fight until you’re tired of fighting. Then change weapons and fight some more. Do unarmed fighting. Repeat. Repeat. Repeat. It appears that while you are doing practice training your stats - Strength, Agility, Vitality, Sword, Axe, Mace, etc. go up, up, up. And you don’t take much damage so you can keep fighting for a LOOOOONG time. Time doesn’t appear to advance while you are doing the “training” (at least I didn’t notice the lighting changing over an hour or more of this.
If you leave the arena and come back the training with practice/real weapons option will have disapeared. So if you need to quit for a while hit ESC and leave the game sitting in the configuration menu.
You get three (I think) bandit camps to wipe out outside of Ratay. Use them to max effect and you can come out with bulging muscles, incredible vitality, and dancing like a … (you know what I mean).
When those three are done you can do more by cleaning up Cuman camps outside of Talmburg - these are not so easy to clean up though.
If you try “real” weapons, expect to get your head handed to you - unless you are really good. The training officers won’t kill you, but they’ll take you down to within an inch of your life. Be sure you have bandages before starting, you’ll need them. Also be sure you have a Lazurus potion (or three), you’ll need to heal at the training ring. If you leave to get healed, no more training until you clean up the next camp.
And strangely, if you do the camps out of order, turning in the wrong set of spurs won’t get you anywhere with the training officer (which seems rather strange - they’re bloodthirsty for souvenir ears but persnickety about spurs… go figure)