Forcing

From A Wheel of Time Wiki

Forcing is a technique used in training with the One Power (however it also happens by accident) to grow stronger in its use. It is considered dangerous because it requires drawing more of the One Power than one can knowingly handle. The benefit from this is that if the channeler is not destroyed or burned out by this process, they have quickly managed to increase their strength with the One Power. It's mostly used by the black tower who think it the best way to get their "army" ready in lesser time. Those who die of this kind of training in the black tower are refered to as training accident. the use of forcing is banned inside the white tower.