First, some basic info 15, female, 5'9" I weigh 132 lbs, waist measurement of about 28 and a supposed body fat percentage of 16% (According to some online calculators) I've eat very healthy and workout everyday. My goal is to have a flat stomach/abs by July, which would give me a little more than a month. My general question is- is this a realistic goal? Also, Ive read contradicting info everywhere.. some say that 20 minutes of HIIT is ideal for fat burning, some say that prolonged, steady running is better. I'm a runner, so I find 20 minutes of HIIT rather easy. But the books say that by running/doing cardio for more than twenty minutes will just counteract the strength training I do and break down lean muscle mass. Would the muscle still be depleting if I ran for twenty minutes in the morning, and twenty minutes at night, per say? Or would this have the same muscle-eating effect? For my goal- abs- what is a good plan? Some kind of exercise/fitness guideline would be wonderful. Up until now Ive been running anywhere from 30-60 minutes a day, either in intervals or steadily..