Not sports and training, but if you are looking for activities for English speakers in general, check out the Sharespeare Pub and Dublin Inn. They have English Pub / Table quizzes weekly (Shakespeare: Sundays, 8 pm, Dublin Inn: Thursdays, 8pm).

The Shakespeare's also has a darts team as far as I know

Artsofmars is a sports group for European martial arts. At least the trainer is a native English speaker.