also: じしゅトレ
noun
independent training; self-directed practice
Abbreviation of 自主トレーニング. Used especially in sports for training done on one's own, without a coach or team.
オフシーズンは自主トレーニングで体力を維持している。
During the off-season, I maintain my fitness through independent training.
監
On days without the coach, the players do self-directed practice.