Do Sit-Ups Ruin Your Posture?

Every few weeks, someone will tag me in a Facebook thread where people are arguing about the negative effects of sit-ups or crunches on posture. Typically, someone will claim that people are already sitting all day long and then question why would we dare put them into flexed postures during their training. They’ll also claim that performing sit-ups or crunches leads to negative postural adaptations such as kyphosis and forward head posture.

Trust me, I understand the sentiments. On weekends, when I don’t train myself or any clients, I tend to sit for much of the day trying to catch up on reading and writing. I can certainly feel the effects of such sitting on my body. Do this day in and day out, and I’m certain that it will have a negative impact on posture and function.

However, luckily we have strength training to prevent these negative postural adaptations. I suppose that now is a good time for a disclaimer. Posture and pain are not well-correlated. You see people with the most jacked up posture in life who exhibit no pain whatsoever, people with “ideal” posture who are in pain, and everything in between.

I do feel that for optimum performance and function, one should pay attention to postural adaptations. To list an example, most powerlifters tend to exhibit internally rotated shoulders due to years of heavy bench pressing. In fact, many sports lead to postural adaptations, and while these are usually favorable for performance, they can sometimes be suboptimal for longevity. Therefore, I definitely feel that it’s important for lifters to pay attention to posture.

That said, if you simply conduct proper strength training and conditioning, posture almost always “takes care of itself.”

I do not feel that we should give too much concern about the individual postural effects of every single exercise and should instead just strengthen all the muscles in the body and focus on the postural effects of the entire regimen as a whole. For example, I’ve long heard from strength coaches and physical therapists that we should never strengthen the psoas. What do they think happens when we sprint? Sprinting requires extremely intense hip flexor contractions. I’ve long heard from strength coaches and physical therapists that we should never strengthen the upper traps. What do they think happens when we deadlift, farmer’s walk, and overhead press? Deadlifting and farmer’s walks require extremely intense upper trap contractions, as does overhead pressing. Do these same strength coaches and physical therapists want us to avoid running, deadlifting, carrying, and lifting overhead?

Strengthening muscles builds flexibility too! 

What many people fail to understand is that the dynamics of full range muscle contraction leads to the maintenance of flexibility. Hell, most studies that compare strength training to stretching show no differences in flexibility gains. In particular, eccentric contractions will prevent muscle shortening (it actually builds sarcomeres in series). This is why I like straight leg sit-ups off the glute ham developer (stopping at a torso parallel position) and crunches off a Swiss ball or an ab mat. However, make no mistake about it, if you play sports, you will be forced to strengthen these muscles.

If you train like an athlete, there’s simply no way to avoid working all the muscles!

Now, I want you to know that I’ve done my homework. I’ve studied spinal compressive and shear forces, along with muscle lines of pull, and other biomechanical topics. I’ve also trained for over 20 years, worked out with tons of different training partners, and trained hundreds of individuals myself.

These days, I don’t perform or prescribe a lot of abdominal/core exercise. Since you get a lot of overlap during full body exercises anyway, you don’t need that much stimulus to achieve impressive levels of core strength and stability. My favorite core exercises right now are the RKC plank, hollow rock hold, and band rotary hold.

However, when I had my Scottsdale personal training facility Lifts, every single client performed two abdominal exercises every day. We usually paired up a linear core exercise with a lateral/rotation exercise and did 1-2 sets of each. For example, straight leg sit-ups and 45 degree side bends, or weighted planks and side planks, or Swiss ball crunches and side crunches, or hanging leg raises and side bends, or foam roller abdominal holds and landmines, or ab wheel rollouts and Pallof presses. You get the point.

As you can see, we performed both dynamic as well as static abdominal movements. We had 40-50 clients coming in 2-5 times per week, and not a single lifter ever experienced pain or injury from any of these movements! If they were as dangerous as they’re purported to be, then I would have expected at least several incidents of pain and injury. Moreover, no client’s posture “eroded” over time. Contrarily, many of my clients started exhibiting “better” posture as they trained with me and my trainers.

Why? Because we strengthened the hell out of the backside of the body! Sure we did our pressing and trained our arms and abs/core. But we spent more time strengthening our glutes, hamstrings, erectors, traps, rhomboids, and rear delts. We performed all types of deadlifts, rows, hip thrusts, back extensions, chins, pulldowns, reverse hypers, good mornings, pendulum quadruped hip extensions, and more.

If you strengthen the entire body, including the traps, delts, bi’s, tri’s, pecs, lats, rhomboids, erectors, abs, obliques, glutes, hip flexors, quads, hams, adductors, and calves, the body tends to “fall in line.”

If you only trained the abs, maybe this would lead to kyphosis over time. If you only trained the hip flexors, maybe this would lead to anterior pelvic tilt. If you only did push-ups and pull-ups, maybe this would lead to shoulder internal rotation over time. But you don’t do this. You train your entire body. Because you read this blog, I know that you know the importance of strengthening the glutes and the whole darn posterior chain for that matter. So the abs and glutes balance out the erectors and hip flexors. The scapula retractors and rotator cuff muscles balance out the pecs. The rear delt balances out the front delt. The lower trap balances out the upper trap. The hams balances out the quads. The entire body is strengthened and posture, function, and performance is improved.

Posture isn’t the problem with most beginners; weakness is the problem! 

Weak abs, weak glutes, weak erectors, weak hamstrings, weak quads, weak pecs, weak arms, weak shoulders, weak hip flexors, weak lats, weak scapula retractors, and weak calves. They’re weak everywhere. You strengthen all the muscles through intelligent exercise selection, and voila! The body shores itself right up.

Short or long does not equal strong.

In the case of sitting, certain muscles will be held for long periods of time at long lengths (ex: erectors), and certain muscles will be held for long periods of time at short lengths (ex: psoas). They will gradually adapt in length to accommodate the persistent posture. However, this doesn’t make them weak or strong. Exercising makes them strong.

It’s all about balance!

The way I see it, if you’re going to claim that negative postural adaptations are occurring, then you need to back it up. I’m aware of no research that suggests that adhering to a well-balanced full body strengthening regimen leads to negative alterations in posture. Anecdotally, I can confidently claim that quite the opposite occurs. And if there is no published research on the effects of a balanced strength training program on postural adaptations, then we can then look to anecdotes to help us guide our decisions.

I give you the ultimate case study – Herschel Walker!

Check out the interview below. Herschel has done 3,500-5,000 sit-ups every day since he was a kid. He’s currently 51 years old. In fact, he credits this daily regimen for keeping him healthy and strong over the years.

[youtube=https://www.youtube.com/watch?v=46o0to59LIY]

For simplicity’s sake, if we assume that he started at the age 15 and performed 4,000 sit-ups per day, we’re looking at almost 1.5 million sit-ups per year and over 50 million sit-ups in his lifetime! 

50,000,000 sit-ups! 

Here’s a hilarious 1989 video where you can see how Herschel trains:

[youtube=https://www.youtube.com/watch?v=OQ-v4M2q4jQ]

If you look at the pictures at the bottom of this article, I think you’ll agree that his posture looks just fine. It hasn’t eroded over the years. Sit-ups and crunches will not turn you into Quasimoto. Herschel has always made sure to train his entire body with sit-ups and push-ups along with exercises such as pull-ups, dips, sprints, squats, lunges, sled work, hill sprints, and carries.

I can already anticipate the opposing argument – “But Herschel is a freak!” Good point, except that we have thousands of these examples. Going with extreme cases, we have Manny Pacquiao, who does 2,000-4,000 sit-ups/crunches per day and has great posture.

[youtube=https://www.youtube.com/watch?v=PTrgpZ9OUSY] [youtube=https://www.youtube.com/watch?v=da8fbd9ivVc]

I’m not advising you to do thousands of sit-ups per day like these guys. What I am saying is that you do NOT need to fear doing 2 sets of 20 reps, using weight if need-be. 

Just like most bodybuilders, who still have good posture.

Just like most martial artists, who still have good posture.

Just like many Olympic athletes, collegiate athletes, and pro athletes, who still have good posture.

If Herschel can do 50 million sit-ups and not have poor posture, I’m pretty sure you can do 40 reps per day and be fine, as long as you use good form.

It’s time we stopped perpetuating this nonsense and simply advised people to train the entire body properly. 

You can do your sit-ups or crunches, just make sure you’re doing deadlifts, hip thrusts, and rows. Make sure you’re keeping your lumbar spine in mid-ranges and avoiding excessive lumbar flexion. This can be achieved by keeping the chest tall and pulling with the hip flexors in combination with the abs during sit-ups, and by only raising the torso to 30 degrees relative to the horizontal during crunches. Just do a couple of sets and don’t go overboard on the volume.

If you don’t like crunches and sit-ups, then don’t do them. There are plenty of other great abdominal exercises such as RKC planks, hollow body holds, and band rotary holds. Whatever you do, make sure you strengthen the posterior chain in concert.