Unless you're cutting with AS, I wouldn't do sprints or run...unless you don't mind losing a significant amount of muscle mass. If you just want get ripped, I agree, sprints will get you there....but if you want to keep your hard earned muscle. Then low to moderate cardio is what you want to be doing. Like walking on a treadmill at 12-15% at a speed of 3 MPH. for 40 mins. This will spare muscle and burn fat.