New Delhi, Aug. 22 -- When the goal is a flatter stomach, many people's first instinct is to drop to the floor and crank out hundreds of crunches. But here's the hard truth: you can't "spot-reduce" fat from your belly. To see your abs, you need to reduce your overall body fat, and that requires exercises that fire up your metabolism and build functional core strength. A combination of high-intensity and strength-focused exercises is the key.

Why aren't crunches enough for abs?

While traditional crunches do target the rectus abdominis (the "six-pack" muscles), they are an isolation exercise. They don't burn a significant number of calories, and they neglect the deeper core muscles, like the obliques and transverse abdominis, which are es...