Starting again

[Race Director]

I'm a former active runner (over 10 years now) and I'm trying to get back into shape again. I've started slow, with running about a mile a day, but after the first couple days, it doesn't make me sore anymore (but it will make me tired while doing it). Should I already be upping my mileage? I'm thinking I should just be treating that as a warm up, is that a good idea?

Any advice would be helpful, thanks!