Where is the cardio area?
'Cardio' is stressed on the first syllable: CAR-dio. 'Zona' = ZO-na.
Ask this on your first visit to orient yourself in a large gym where the cardio machines (treadmills, bikes, ellipticals) may be in a separate section from the weights area.
'Dov'è' = where is (contraction of 'dove è'). 'Zona' = area/zone. Italian gyms are typically divided into: 'zona cardio' (cardio area), 'sala pesi' (weights room), 'sala corsi' (group class room), 'zona stretching' (stretching area).
Dove sono le macchine cardio?
Where are the cardio machines?
Asking for machines specifically.
C'è una zona free weights?
Is there a free weights area?
Asking about the free weights zone.
Dove posso fare gli esercizi a corpo libero?
Where can I do bodyweight exercises?
For bodyweight training area.
Many Italian gyms are located in basement ('seminterrato') or upper floor spaces in urban buildings, a legacy of the 1980s fitness boom when gyms were squeezed into available city-centre spaces. This is different from the large stand-alone gym buildings common in the US or UK.