Is it correct to say: "Keep me fit"?
I want to say that I keep myself fit doing some sports, such as swimming, playing tennis dcc...

Question

Is it correct to say: "Keep me fit"?
I want to say that I keep myself fit doing some sports, such as swimming, playing tennis dcc...

Answer

You could say "I keep myself fit doing..." or "Doing ... keeps me fit".

You're sentence is fine.

Answer

I think you would say keeps me fit 
Examples:
Running keeps me fit.
Eating healthy food keeps me fit.

Answer

To keep fit, I run, go to the gym, etc.