Crunches won't give you six-pack abs - but they can cause injury
According to Don Saladino, a celebrity fitness trainer (who is known for sculpting the bodies of Blake Lively and Ryan Reynolds) and the owner of Drive495 gyms in New York City, that's because doing crunches doesn't result in more prominent abs.
Instead, sit ups can actually cause us harm - and whether we'll get a six-pack is dependent upon our diet, not our ab work, the trainer said.
"Spot reduction is the idea that by doing thousands and thousands of crunches is going to melt the fat away. That's completely false," Saladino told INSIDER. "You cannot out-train a poor diet."
If someone is looking to suddenly develop washboard abs, they need to reduce calories and eat well (in addition to working out), instead of subjecting themselves to crunches. Furthermore, Saladino added that sit ups can be damaging for most people.
Those of us who "sit in a chair six to 10 hours a day" are constantly in a state of flexion, which means that our body is bent, the trainer said. Leaving our office jobs to go to the gym and do crunches merely puts our body in a further state of flexion - and can lead to lower back injuries.
"You do not need a crunch. There are other exercises out there that can get a lot of stimulus to the abdominal wall without putting your back into flexion," Saladino said.
In lieu of crunches, the trainer recommends people who want to do core work instead turn to planks - which involves holding oneself in a push up position with the elbows bent at 90 degrees - or his personal favorite, bear crawls.
"I love bear crawls; that's one of the best exercises for for core," he said. "It's a locomotion pattern. You're in a plank position, but your hips and shoulders are moving."