Wow, means I'd rather train my fast trainers rather than play them in matches since they improve faster through intensive training

Quote Originally Posted by Killerbee View Post
They get experience points relative to the amount of time they played (and thus gained experience/used condition). So you have to play them for a full match in order to gain the full experience points.
It's not a massive difference in gain compared to regular training though, so don't worry too much about it. Only the man of the match gains an amount that he wouldn't be able to gain with regular trainings.