Because i run i tend to use too-beat-up-to-run-in trainers at the gym... Just a normal general purpose gym show should do but i do find there are often better treads on ones meant for running. It depends on your foot shape what is comfy but i need good support for my feet (tend to over pronate with my right foot) and like a well-padded, wide-soled shoe for good stability. Do you have a good fitness store with properly trained assistants who can advise you nearby?

Bx