I've pretty much cut out all gym cardio since it's been a struggle just to retain muscle mass on my puny frame. I bike to the gym and do weights a couple mornings during the week, then bike from there to the office for a brief 2.5 mile commute, which I use as an opportunity to do one long sprint.

I definitely feel a significant energy sap when I bike after lifting, even if I'm just doing upper body stuff.