Sit-Ups: Good or Bad?

The best thing for your abs since cutting out sliced bread? Or a back injury waiting to happen? We take a fresh look at the humble six-pack sculptor

Words: Tom Ward

GI Jane does them hanging upside down from a punchbag. Rocky Balboa does them in a wintery Russian shed, kicking his legs overhead like the show-off he is. Patrick Bateman can do 1,000. And, for a more contemporary reference, see: pretty much any recent boxing or martial arts film from Creed II to Million Dollar Baby.

Yup, when it comes to getting in shape, for men and women, the sit-up has ranked alongside the push-up and the squat as muscle-sculpting 101. But, as the science of fitness and biomechanics advances, the sit-up has come under fire.

“Sit-ups once ruled as the way to tighter abs and a slimmer waistline,” explains a 2021 article from Harvard Health, going on to point out that exercises like the plank have largely supplanted the sit-up as the ab-trainer of choice. So why the change?

“Sit-ups are hard on your back," the article continues. "They push your curved spine against the floor and work your hip flexors, the muscles that run from the thighs to the lumbar vertebrae in the lower back. When the hip flexors are too strong or too tight, they tug on the lower spine, which can create lower back discomfort.”

So, should we skip the sit-up altogether? To help bring you some answers we asked Robert Utley, founder, Real Body Performance, PT & movement specialist Tom Cuff-Burnett, and Mitch Raynsford, strength and conditioning coach for P3RFORM to, ahem, crunch the data.

What are the benefits of the sit-up?

First thing’s first, the sit-up is easy. As in, you can do it anywhere. “All it takes is to flop on the floor and get going,” says Utley. What do you actually gain from it? “Sit-ups focus predominantly on the core-stabilising muscles of the torso: rectus abdominis, transverse abdominis and obliques, which add strength and stability in your anterior chain – the muscles along the front of your body,” explains Cuff-Burnett. 

“They also promote good posture by working your back extensor and gluteal muscles, contributing to greater flexibility of the spine and hips, which can improve circulation, reduce stress and keep your hips, spine, and shoulders aligned,” he continues. A great all-rounder, then.

Not only that, but Raynsford explains that looking after your core is key for maintaining flexibility and stability as you age, and the sit-up is an easy way to do so. But it isn’t without its risks.

Can sit-ups damage my back? 

In short, yes, of course they can. But so can sitting at a desk all day. “Everything is bad for your back if done wrong,” says Utley. “I’ve pulled my back sleeping, sitting on the toilet and getting into the bath. The key to everything is to ensure you focus on how you move.”

Cuff-Burnet agrees; done properly, the sit-up is your friend. The problem is, there are a lot of ways they can go wrong. “The issue with sit-ups is that they are often poorly executed with people leading with their head and curving their spine to initiate the movement,” he explains. 

Bend your back and you can compress the spinal cord, instead of putting the burden of the movement through your abs, as you should. 

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How do I avoid injury?

Sticking with the sit-up? Then pay attention to Cuff-Burnett’s advice about avoiding  common errors:

• Craning the neck: “Typically caused by people placing their hands behind their head and pulling their neck forward as they sit up. Easily avoided by simply placing the hands across the chest.”

• Uneven surface: “Try to find a flat surface to do them on, ideally with an exercise mat or specific ab-mat, to help reduce pressure and impact on the back.”

• Slapping the floor: “This happens when you don’t use the abdominal muscles to control your descent from the top of the sit-up and end up landing hard on the upper back. Think about ‘unfurling’ the spine as you lower, placing each vertebra down one-by-one to return to the ground.”

So what else can I do to hit my abs?

We’re glad you asked, because while the sit-up does have a place in your workout, the variety of ab variations out there is near-endless. 

The Crunch

“A crunch is often a better option as it allows a neutral upper spine and allows you to focus on contracting the rectus abdominus without unnecessary strain elsewhere,” explains Cuff-Burnett.

Lie flat on your back, knees bent, hands across your chest. Point your chin down slightly as though you’re holding a tennis ball under it, then engage the core to lift your shoulders just a few inches off the floor. Hold, and lower back down for one. 

The Pallof Press

“This hits all aspects required of a strong and stable core across multiple planes,” explains Raynsford.

A bit different, this one, as you’re actually going to be standing up for it. Angle yourself at about 90 degrees to a cable machine, the cable attachment about chest height. Pull this to your solar plexus, so that you’re under tension, then extend your arms forward, straightening them out in front of you for one. Enjoy the burn through your abs. You’re welcome.

Straight leg sit-up

“Perform a sit-up as you normally would, but instead of bending your knees, keep your legs straight out in front of you,” advises Cuff-Burnett. “This will reduce the role of your hip flexors and isolate your abdominal muscles, making the movement a whole lot more challenging.”

The deadbug

“A staple in my own training as well as programming for my athletes, the deadbug is a fantastic anti-extension exercise to challenge your bracing ability and anterior oblique sling strength,” says Raynsford.

Perform it by lying on your back with your arms straight out above you and your knees at a 90-degree angle, directly over your hips. Extend opposite arm and leg to your limit. Keep your lower back on the floor to ensure core engagement and return back to start position, then alternate for desired reps.

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