When people think of an exercise to strengthen and tone their abdominal muscles, they often think of crunches or sit-ups as the go-to workout. In fact, crunches are probably one of the worst exercises to do … for several reasons. The major reason not to do crunches is that they strain your back muscles and they can cause the discs in your back to bulge, causing lower-back pain and potentially causing a herniated disc. In addition crunches don’t target all of the abdominal and core muscles. For a strong core, you need to work all of the abdominal muscles in the trunk: the rectus abdominus (your middle “six pack” muscles), the internal and external obliques on the side of the rectus abdominus (prevents “love handles”), and the deeper transverse abdominus(TvA) muscles which play a pivotal role stabilizing the torso.
Some fitness trainers will argue that crunches, if done correctly, are good for abdominal strength. But there are so many other exercise options, that it’s not worth the risk of a painful back. Some very good exercises for the core are face down planks and side planks, plank jacks, push-ups, walk-ups, as well as lunges and squats, if done correctly.
And also be aware that no amount of ab work by itself will give you a toned torso. If you’re not eating a healthy diet and fitting in cardio exercise, you may have toned ab muscles but they’ll be hidden behind the belly fat.
Train smart. Race fast.