- The standing oblique crunch is a popular ab exercise that can injure you if done incorrectly.
- A personal trainer said she stopped doing the exercise in favor of alternatives that avoid back pain.
A popular core exercise may look like it gets results, but can leave you with aches instead of abs, according to a personal trainer.
The standing oblique crunch (sometimes called a side crunch or side bend) is a common move to sculpt the sides of the core, but it's difficult to do correctly and often leads to injury, said Cat Kom, trainer and founder of Studio SWEAT onDemand.
"I'm not a fan. I see them done often and the next day people say 'My back hurts.'" she said. "If I ever see any of my trainers doing it, I will stop them."
The exercise involves holding a dumbbell, kettlebell or other weight in one hand at hip height, then bending at the waist to lean sideways, lowering the weight parallel to your body and raising it again. It works the muscles called the obliques, one of the largest muscle groups of the core, located on either side of your midsection.
The problem is that most people will struggle to properly target the abs, and instead put stress on other muscles, like the back, according to Kom.
"It's really hard to get your body in the right position. Your body isn't really meant to flex to the side so it doesn't handle that load well," she said.
The result is often soreness, and not in a good way, and Kom said she's stopped doing standing oblique crunches in favor of safer alternatives.
"I used to do them as a younger trainer, but there are so many things you can do to work that same area." Kom said.
Safer alternatives include heel taps or bicycle crunches
There are better options for lighting up your core that help target all the muscles of your core for strong, well-rounded abs, without straining your back, Kom said.
One option is heel taps, performed by lying on the ground with your knees bent and feet planted a short distance from your hips. From there, reach one arm straight down along the ground to tap your heel, and repeat on the other side, alternating to work both sides of your core while supporting your spine.
Kom also recommends bicycle crunches. The exercise involves lying on your back with your knees bent and feet off the floor, contracting your abs to bring your elbow to your opposite knee, pressing your lower back tightly into the floor throughout the exercise.
Done correctly, bicycle crunches work nearly all the muscles of your core, from your obliques to the transverse abdominis.
The key to bicycles, as with almost any core exercise, is to go slow, emphasizing the control and tension on the target muscles, according to Kom.
"If you just slow it down, you're going to get twice as much out of it and are more likely to avoid injury," she said.
If you want to use weights to build stability and muscle, strengthen your core and back with moves like a farmer carry, suitcase carry, or deadlifts Noam Tamir, founder and CEO of TS Fitness, previously told Insider — but good form should always be your first priority.