The cooldown system in R3K is very unique. The higher the Lv of your city infrastructure, the longer cooldown it will have. However, in
General Training and Equipment Upgrading, the cooldown is the same.
(For General Training, 2 mins each time; for Equipment Upgrading, 1 min each time) And when the added cooldown reaches the cap, you
will have to wait, unless you use gold to get instant cooldown. Example :