There. Hopefully that title got your attention.
I actually don't hate sit ups. What I hate, is when I've worked numerous different core exercises in to an hour in the form of planks, lifts, chops, throws, anti-rotation presses... and still, at the end of the hour, the client says "When are we going to do some core?".
To which I ask why.
"Because I'm feeling soft around the middle."
At which point, I have two choices - I either become a lecturer (and watch them glaze over and ignore what I say anyway) or simply point out that we've done lots of core work, and we have run out of time... only to see them grab a mat and do 100 crunches just to get the "burn". (You'll note that at no point do I consider actually doing the sit ups...)
So, in an effort to save myself the time, perhaps by posting a blog on it I can simply refer them over if they actually care enough to find out the answer...
I don't hate sit ups. To be honest, I don't believe that there are a limited cycle of spinal flexions at which point the disc herniates... I think that everyone has different tolerances, and some could do 100 sit ups and 100 crunches every morning, noon and night and never have a problem, and someone else will lean down to tie their shoes after 20 sit ups and "pop" goes the disc (actually, if it really had a sound I think it would be more like "splooge", but that's just weird and less dramatic). I have no science to back this up - just anecdotes and experiences.
That being said, I also don't think any of us know which type of person we, or our clients, are. Are we training with a back that's 27 flexions away from a herniation, or 27,000 flexions? And how long do we want to take the risk, when there are so many other better solutions that don't run the same risk? Furthermore - when we consider that so many of us sit in the position of the model in the picture, how many are actually just maintaining that forward lumbar flexion - and putting an endless stress on the spine (discs) before they ever even sit down?
So, while there are always exceptions to the rule (people with injury, or who's rectus abdominus is so weak that they can't sit up out of bed, or the occasional sport like MMA), the sit up is pretty low on the list in terms of risk and reward. You get far better "bang for your buck" AND you get better spinal safety without the dreaded sit up.
And that's about all I have to say about that, for this time around...
P.S. As Yoshi says - if you're looking for your abs, they're in the kitchen. Stop eating like crap, don't do sit-ups.... and you'll likely still get a six-pack.