The system was changed, time ago the main star regulated the XP win of all skills, so once a player won a star, the XP win in training -training speed- decreased a 15% aprox. ,but once the mutants appeared and many stuffs happened, like 1500% players, or many managers training mutants till 340% ..there was a update, that changed the source that regulates the Training Speed, and now are the own skills, individualy what regulates it's own XP gaining. So the Higher is a skill, like speed, tackling etc. the less XP wins and is like the whole player have that AvQ.
7* speed = 7* player ashard as it was time ago to train.