Just checked on a reserve team: for a certain amount of green boosters (5-10ish?), depending on how much time remains until the next rest, your entire team will get a 5% condition increase.
Could be worth it in some cases where you need to condition-boost many players. but seeing how 1 green booster heals 15%, for this to be worth it, you would need to be healing roughly 3x the amount of players compared to the amount of boosters it would cost to get the rest.