well thx guys, but have you even read my question?

smoggie- putting them to rest doesn't make them rest. they gain 5% condition every 3 hours no matter what intensity you chose. if you will put them to rest they will simply won't participate in the trains.

forestry- you will get rest pack for every game you played and did substitue. you will also gain them from the training facilities, max of one rest by gift for day, or in exchange of expensive tokens. i am well aware to that.
saving them for when in real need is obvious, the question is will they do something if i use them right before the game or only if i use them before the daily maintaince.