Exercise in Santa Cruz

Hey everyone, This site is full of great information! I'm studying abroad in Bolivia this semester and have used it many times. I'm now in Santa Cruz for the month and I'm staying fairly close to the city center. I'm having a hard time to find anywhere to exercise-most of the gyms I've seen have been small rooms with some weights or Premier on San Martin which is incredibly expensive and not very close. Does anyone have any good recommendations for gyms within walking distance of the center or at least easily accessible via micros? It doesn't need to be anything fancy-I just want some treadmills or ellipticals and weights. Any thoughts would be great!

Thanks!