yeah, don't get into steroids. Steroids don't only raise testosterone levels, but they also raise estrogen levels which could give you bit*h tits and other unwanted things to happen to your body. Another thing with steroids is that you have to ween yourself off of them once you start. You can't come off cold turkey, because you can cause serious harm to your heart and other important internal organs. People don't realize, but your heart is a muscle and when you take stuff like steroids, your heart will grow to which isn't good. To work on your cardio, the best thing for you to do is RUN. Run alot , thats what I do. I run about 4 miles a day, 2 miles in the morning and 2 miles when I get home from work. The only thing I use is Xyience NOX-CG3 and XNGF ( Xtreme natural growth factor ) its all natural capsules used to enhance body mass and reduce bodyfat. Stick to the most natural solutions, the more natural you do everything the better off you will be. Anything you take, you have to work out. Like those shakes, if you don't work out while drinking them, you will get fat. I watched a friend drink them everyday all day and he never worked out and he gained alot of FAT.