If you are just alternating upper and lower, training 5 days a week probably is too much. I lift 5 days a week, but a different body part each day so that no body part gets directly worked more than once a week. If you want to lift 5 days a week, I'd suggest changing your "split" so that you don't overtrain. You can work major muscle groups with 4 days rest between workouts. Here are a few sample splits just to give you some ideas:
The "work legs twice" split":
Monday: legs
Tuesday: shoulders and abs
Wednesday: back and biceps
Thursday: legs
Friday:chest and triceps
The once a week routine:
Monday: chest
Tuesday: shoulders and abs
Wednesday: legs
Thursday: biceps, triceps, abs
Friday: back
IMO, you should be too tired on leg day to do much cardio
How long have you been lifting and how much time do you spend during each session? Do you lift heavy to near failure? If so, you are overtraining.
Mel