Why Crunches Alone Won't Burn Belly Fat
If you're trying to burn belly fat and tone your abs, it's almost guaranteed that you're performing Crunches. If you are, you are not alone. Many gym-goers target their belly fat with this popular exercise. (Learn if you should do Crunches.)
It makes sense that repeatedly contracting your abs will burn belly fat, because that's the area you are working. Crunches do burn calories—a minimum of 68 calories per 10 minutes; however, working your abs does not mean you will burn stomach fat.
Do Crunches Burn Belly Fat?
A study indicated that abdominal exercise alone, including Crunches, was not effective in reducing local abdominal fat stores. Fat is generally burned in the opposite order it was put on. So if the last place you put on fat was your thighs, they will be the first place it will come off.
Rather than Crunching your valuable gym time away, spend it performing exercises that involve more muscles, such as Squats, Deadlifts, Presses, Rows and Olympic lifts. Because you will be using large muscles, you will burn more calories, develop a stronger core and cause your body to continue burning calories after you complete your workout. (Learn how to build true core strength.)
Ab exercises such as Planks, and even Crunches, won't necessarily cause you to burn stomach fat. However, a balanced workout program combined with these exercises will accelerate fat loss and help you get the stomach you've always dreamed of.
 Vispute SS, Smith JD, LeCheminant JD, et al. "The effect of abdominal exercise on abdominal fat." J Strength Cond Res. 2011.