Muscles aren’t built during activity but in rest. Alternating your weight and cardio routines will allow your body to properly recover. I do it like this:
Monday – Cardio – elliptical
Tuesday – Weights – arms
Wednesday – Cardio – stair master
Thursday – Weights – legs
Friday – Cardio – elliptical
Saturday – Weights – arms
Sunday – REST
Next week I’ll have two leg days since I had two arm days this week. This is how the Body for Life workout program works in case you’d like to pass on wasting money on that.
I do yoga most days and go for light jogs when I feel like it. But overall, this is the base of what a reasonable workout program looks like.
Changing things up also keeps you interested. If you’re on the stair master every single day for 45 minutes, your muscles are bored and I predict you are too.

So true! My routine is similar to yours except I try (for the most part; life sometimes gets in the way) to do weights for arms and legs one day, cardio the next, and switch back and forth. I do my abs every day. I read somewhere once that they are the only muscle group one can safely work each day.