I HAVE to work legs today, and pretty hard, but I also need cardio. Unfortunately my DS is sick today and now my DD just came home not feeling too hot so I don't have the 2 hours needed to get a good w/o in. Does anyone know if this premix is good enough for a leg day? I want to w/o but I don't want to feel like I slacked today, I've never done this premix. Thanks for all the input