Translation guide
A large room or building for indoor sports, exercise, or physical education. In Japanese, the word depends on the context: school gyms, public sports halls, and fitness gyms use different terms.
The large indoor space in a school used for PE classes, assemblies, and sports.
Standard term for a school gymnasium. Used from elementary through high school.
We played basketball in the gymnasium.
The school assembly is held in the gymnasium.
A municipal or community facility for sports and events, often larger than a school gym.
A commercial facility with exercise machines and weights for personal fitness.
A large indoor stadium for professional sports or big events.
体育館 is a gymnasium (large hall for sports), while ジム is a fitness gym with machines and weights. Using 体育館 for a workout gym sounds odd.
I do strength training at the gym.
Both are 体育館, but you can specify 学校の体育館 (school gym) or 市民体育館 (municipal gym) if needed.
Often used for larger public sports complexes that may include a gymnasium, pool, and training rooms.
We played volleyball at the ward sports center.
He's learning boxing at a sports gym.
A fitness club, often with a pool, studio, and gym area. More formal than ジム.
I go to a fitness club.
Sometimes used for smaller competition venues, but アリーナ is better for large-scale events.
The national tournament was held at Tokyo Metropolitan Gymnasium.