is it better to run first then lift weights, or should it be the other way? and why?

I personally do cardio and lifting on separate days. I lift 3 times a week and do cardio 3 times a week. When you're lifting, you should allow your body approximately 48 hours recovery between each lifting session, although you can "cheat" and do upper body one day and then legs the next.

But, regardless of this, if you are going to do them the same day, lift first and then run after so you'll be less tired out and can lift heavier. Good luck!

A BB once told me that you should split your cardio and weightlifting workouts. A lot of trainers say to do cardio in the AM and weightlifting in the PM. But, working out twice a day is difficult for most people. They say that if you are doing cardio first (in your case running), by the time you get to weight lifting you will be fatigued.

Lift first. Running will just tire you out and you wont be able to lift as heavy and you will be more prone to injury.

I don't know what the experts might say, but I start with stretching, then weights, then running. Seems to work for me.