Crunches Vs Sit-Ups: Which Is Better For Strengthening Your Abs?

Man performing sit-up
(Image credit: SolStock / Getty Images)

If this were a training montage, you wouldn’t be asking which abs exercise to bust out at the gym. The sit-up, with its greater range of motion, looks far more impressive intercut with chasing chickens and pounding punch bags than the more minimal movement of the crunch. 

But this is not a movie and you can’t fast-forward through your abs training. You have to spend your precious time doing it so it pays to know which is the most effective. We checked in with Amber Sayer, a NSCA-certified personal trainer, for her take.

Are crunches better than sit-ups for abs?

According to Sayer, the crunch is the superior exercise. “In terms of actually targeting your abs, crunches would be better than sit-ups, because sit-ups require the use of more of your hip flexors than abs muscles,” she says.

The way people often perform sit-ups can accentuate this problem too. “My concern with sit-ups is that a lot of people will hook their feet under something to keep their feet down,” says Sayer. “Then they’re really just using momentum and kind of pulling up with their hip flexors. That can cause injury and it ends up not really targeting the abs well.”

That said, Sayer notes that if you have spinal stenosis, osteoporosis of the spine or you’re pregnant, you should avoid crunches. Otherwise, crunches beat sit-ups for training your abs any day of the week.

The crunch has one other major advantage over the sit-up: It trains more of your core than the sit-up, and you’re likely to be weaker in that area than your rectus abdominus. “Performing [the crunch] properly will work other core muscles like the transverse abdominis and pelvic floor,” says strength and conditioning coach Fiona Scott, who contributed to our guide to how to do a crunch.

About Our Expert
About Our Expert
Amber Sayer

Amber Sayer is a fitness, nutrition and wellness writer, and editor at Marathon Handbook. She is a UESCA-certified coach in running, endurance nutrition and triathlon, as well as a certified personal trainer. She has two master’s degrees, one in Exercise Science and one in Prosthetics and Orthotics. 

Lois Mackenzie
Fitness writer

Lois Mackenzie is a fitness writer working on news, features, reviews and buying guides for Coach and sister site Fit&Well. Lois is a hill walker and avid runner who has just completed her first marathon. Before joining Coach, Lois worked as a senior SEO reporter at Newsquest Media Group.