how long does it take for your players to get back up to their maximum energy level
That depends on what your training intensity is set at.
Normal training - each player gains from 0-2 percentage pts per training session (each week).
low training - each player gains from 3-6 percentage pts
very low training - each player gains from 5-6 percentage pts
any players that you can rest gain @ 10-13 percentage pts IIRC.
This information and the gains/losses from the various training settings can be found in the FAQ (except for resting).
In my opinion, it's not worth it to train any higher than normal training. The gains are too low for the penalty. You would have to train on maximum for around 30-35 wks to gain 1 extra pt on a focus trained skill.
