outdoor practice
Sumo term for training held outdoors, often in a natural setting like a mountain or forest, as a form of conditioning.
力士たちは夏の山稽古で体力をつける。
Sumo wrestlers build up their stamina during summer outdoor practice.
Compound of 山 (yama, 'mountain') and 稽古 (keiko, 'practice, training'), referring to training conducted in the mountains or outdoors.