Basically, I get absolutely zero cardio. I'd like to work it into when I go to the gym, but I'm already there for an hour, and I don't always have the time or energy left after a bob starr/christophers routine. So... Aside from just making time (which is obvious), what about replacing some of my strength training with cardio? Like 3 weeks worth of strength, 1 week of cardio, repeat. Something along those lines. Would I be sacrificing too much regarding strength building?