The nearest gym is at the hotel sensol on camposol, but they have very little equipment and it is expensive. the membership does not qualify you to use the hotel spa facilities within the price. I think there is a gym near the bowling alley in mazarron behind the mercadonna supermarket but dont know any other info on that one.
not much help but will give you a starting point, why do you want running machines when you can run around the wonderful countryside of cda??? other than it gets too hot in the summer!!
Barbara