Spinning class and running.

I run about three miles three days a week.  A spinning class is offered at my gym, and I was considering going to the spinning class two days of the week that I'm not running.  I also would do full body weight lifting on the days that I'd be spinning. Would this be too much?

Too much for what?

Spinning is an excellent cross-training tool for runners -- great cardio benefits without the pounding on the knees and other joints.  However, I would not spin and weight lift in the same workout, unless your weight lifting routine is upper body only on those days.  If you lift lower body before you spin, your legs will be gone for the ride.  If you spin before you lift lower body, you won't have the energy in the legs to really hit the weights the way you should.  You need to let yourself recover after heavy cardio or heavy weights.

Thank you for your advice!

Add new workouts slowly. Athletes can handle some serious workout regimens, but they had to work up to that level of fitness. You can do it too, but not all at once (it sounds like you're trying to add spinning and weightlifting at the same time - maybe I'm misreading). Try adding just one spinning day at a time, doing spinning on different days than lifting, etc. Remember to eat & rest well, too.