Arabic to English Other Sports / Fitness / Recreation Certificate

This is a certificate offered by الاتحاد المصري لكمال الاجسام

There are several sections - وزن , اسم, المنطقة, النادي etc. The first one is

بطولة : الجمهرية صالات خاصة 21 سنة

What I have now is The Republic's Championship in dedicated halls for 21-year olds.

"dedicated halls" is not quite right...What do you guys think it is?

(Also, is it 21 year olds, or the 21st year of the competition?)

Thanks!