nope, academy players are a good option, I writted 108 of progress because was the max. that I saw yesterday in his training, and, in this player, but today he won 129, and I had players that with 18-19 years train faster, and too, in my case, I have to say, that my youngers are very efective. I bought a 50tokens player that did nothing, comparing with some of my young MC's that score more goals in a season... in my case, and I talk only of my case, youngers are loyal and efective players, and a good option, "made in home".
I had a younger called Duran that in a match won +250 of progress, so, if you want to power train a player, one of the academy is a good option.
too I read about the "nordeus gens" that you can buy in the morning, from robot teams... but I never had one of this...

and well, I invite all people that have a young player of the market, to put here the training results, o have a list of the prices per level, thats the idea, because sometimes here, we can see people here asking for this