A two-roomed building, it is located to the left upon entering the galleria. Inside, one can find a boxing ring on the left and weights on the wall. A counter manned by Danny, is to the right, along with a shelf containing some Buffout and stimpaks.
A door behind the counter leads to the officer, where Madden's office terminal can be found, along with an open safe containing more Stimpaks.
Madden's Gym appears only in Fallout 4.