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A toned, flat tummy is a top priority for health-conscious folks—and for good reason: Not only does shedding excess belly fat help you feel lighter on your feet, but research suggests it can lower the risk for heart disease, diabetes, and other serious conditions. While you probably already know that scoring a flat belly requires regular exercise and a healthy diet, Holly Perkins, personal trainer, says many people still think they can speed the process by spot-training their abs.

"I see so many clients who believe they have to do abdominal exercises to change their abs," Perkins says. "Yet strengthening the muscles that make up your six-pack won't actually lead to a flatter tummy. Yes, you need a strong core for balance, good posture, a healthy back—the list goes on. But for aesthetics, ab exercises aren't your best bet." Instead, Perkins suggests lowering overall body fat—something that will ultimately help to whittle your middle—with the help of cardio full-body strength training, and a clean, whole foods-based diet.

To make more time in your training program for the exercises that will actually deliver, ditch these five ab exercises that, according to Perkins, are the biggest waste of time.