Long distance walking (safety) and/or day use gyms?

Hello

I'm taking a very last minute trip to Medellin for a couple of days from Cancun this weekend. It wasn't planned but I've always wanted to visit Colombia and the fights are decent.

I am currently walking long distances (20 miles per day, split into 6- or 8-mile walks). I'd like to continue this in Medellin and I wondered if anyone had suggestions for any areas or particular walks of this distance that would be relatively safe for a gringo during the daytime and early evening? I will be staying in the laureles area.

Alternatively, are there any cheap day-use gyms that I can visit for some of this exercise?

I'm frantically searching as we speak, but if anyone has any tips, I would really appreciate it.

Thanks!