Good to see you here. You know it's depands what you like to talking about. It's your choice :)
Yeah, what do you enjoy doing? I was a little directionless with my blog, then realised I had plenty to say about music so that's the way it went!Maybe you could keep it as a diary for gym stuff?
Pick something that interests you!
I agree with the others, the most important is that you take pleasure writing it :)
Music seems to be popular nowadays.