Right now I am in a cutting phase. I have restricted calories and carbs and raised my protein. I think I have the whole deit thing in check. I have a cardio question. What's the best way to do cardio? How can you burn the most fat and the least amount of protein (muscle)? I have been doing the x-trainer for 30 minutes 4 times a week. I just do the fat burn program that the machine has. I try and keep my heart rate somewhere around 128-130. Any suggestions?