Lifting and running?

Question

When I go to the gym, I lift weights and run on the treadmill, which is better to do first and why?

Answer 1

If you are really pro you can run and lift weights at the same time. But then again you are not pro, so I would recommend riding a bike before your workout and finishing it with a run.  

Answer 2

doesnt matter, just as long as you dont over do either, otherwise whatever you do second will hurt you