As I already said in some other threads, there is pattern in skill gain for two types of players in T11, fast trainers and "flops".
This thread is dedicated to fast trainers, 'cause it's expensive and pointless to power train "flops".
As you all already know, a rest pack recovers 15% condition of a single player. Practice Match and Cardio training would use those 15% again.
I did some maths to calculate how many rest packs you need to train fast players: 1 Quality point up... 1 Star up... Free Kick, Corner or Penalty Kick special ability... and other special abilities.
To train your player 1 Quality point up you will need 15 skill points. That's 1500% skill progress. For a Star up your player will need 7500% skill progress, for FK, CK & PK 4000% and for other SA 5000%.
This pic is pattern range of young fast trainers (age 18-21). All you have to do is to determine the lowest skill gain value (not necessary for all 3 training types, Stretching will do the job and you can multiply it 2x for Cardio and 3x for Parctice Match). The highest skill gain value is always +10, +20 and +30. The range can go up or down depending if player loses or wins a Star, but distance between the lowest and the highest value never change (If it's not 10, 20 and 30, the player is "flop").
So, average value of the range would be like this.
First pic is how many rest packs you need to train the fastest of those 4 previous examples, and the second pic is calculation for the slowest of 4.
So, basically, if you want to power train a player with 18-28% (Stretching) range to win a Star, you will need around 65 rest packs. In game shop you can buy 50 rest packs for 46 Tokens, so 65 packs would be around 60 Tokens. Comparing to this...
Personal Trainer (320 Tokens to win a Star) is completely and absolutely useless and big waste of money...