Academies open where the rent is lower. BJJ and MMA gyms occupy ground-floor units and small industrial spaces in San Marcelino, Patraix, Camins al Grau and out towards Alboraya and the Patacona, while boxing and fitboxing studios stay more central, around Ruzafa and the Eixample. Very few sit inside Ciutat Vella, so training usually means a short metro or bike commute.
Membership follows the gym pattern: a monthly cuota by direct debit, usually a matricula on joining, and often a cheaper rate for two sessions a week rather than unlimited access. Ask whether open mat and the strength room are included in the price, whether there is a permanencia clause, and how to pay for the first month while your Spanish bank account is still pending.
Class blocks are evening-heavy, roughly 19:00 to 22:00, with a midday session in the bigger academies and open mat at the weekend. August runs on a reduced summer timetable before the September intake. On the mats, instruction is mostly Spanish but leans heavily on demonstration, and BJJ terminology is the same everywhere, so a beginner with no Spanish follows along more easily than expected.