Wow, I'm starting to wish I had taken biology in college rather than chemistry. Thanks so much, that answered a ton of questions I had.
Now I remember back in the day I tried a program where I was doing a 30minute lifting routine flush. All heavy weight, low rep but never more rest than it took to move stations. It sure got your heart pumping like crazy, would that activate both the cardio (mitochondria) and weight lifting (mass) aspects you described above?