Ever since Dr. Stuart McGill (professor of spine biomechanics at the University of Waterloo) unleashed his research on spinal health and published his book, Ultimate Back Fitness and Disorders, the fitness industry was awakened to the fact that the typical human sit-up places up to 3,300N of compressive force on the lumbar spine. For those who are wondering if this is a good thing: it's not. As such, when it comes to enhancing someone's "core" strength, I'm almost always going nix repeated spinal flexion in training (i.e. sit-ups), and opt for improving spinal stability. Think pallof presses, landmines, woodchops, single-arm farmers walks, and planks, to name a few.

Or, I may choose a host of anti-extension exercises to give someone their ab training fix, utilizing any of the 20+ demonstrations I give in the video below:

However, should ALL movements resembling a sit-up be avoided like the bubonic plague? I don't think so.

While I do believe that - nine times out of ten - one should train spinal stability in order to correct low back dysfunction, reduce the risk of injury, and morph into a healthy, high-functioning athlete; there are exceptions to the rule.

For example, if I'm training a number of mixed martial artists (which we're consistently doing at SAPT), are you telling me that I never need to help them improve their abdominal strength for guarding?

Or, if helping someone prepare for a military test, should I avoid having them do sit-ups even though the testing protocol calls for a very specific test in sit-up endurance?

(Disclaimer: What I am NOT saying is that you always need to train people in positions specific to where they find themselves in sport (Ex. If I'm training a boxer do I need to repeatedly punch him in the face?). However, sometimes a small dose of a particular training protocol is needed to maximally prepare someone for their respective event.)

Turtle Rolls

Enter the turtle roll. This is a brutal abdominal exercise that hammers the rectus abdominus, along with the internal and external obliques, to both maintain trunk flexion and resist trunk extension. See the demo below:

How to do it:

Wrap your hands behind your head and touch your elbows to your knees
Have a partner SLOWLY rock you up and down, touching your heels to the ground at the top
Brace your abs HARD. Try not to generate any momentum to "swing" yourself up
Perform 8-12 repetitions
A cat walking around you is optional

The beauty of these is that you can do them virtually anywhere, as long as another person is close at hand. It is much harder than it looks to keep your elbows in contact with your knees, especially if your partner is moving you slowly. After you master a bodyweight turtle roll, you can hold a weight plate on top of your head (you won't need much though, trust me).

A couple caveats:

If you have back pain, I'd avoid this one. You can receive plenty of good ab training via other means
If adding turtle rolls in a training cycle, be sure to do plenty of work for the erectors and include a healthy dose of thoracic mobility drills to prevent hyperkyphotic postural adaptations in the thoracic spine. You should be doing this anyway, though....GOSH!!
Don't get too addicted to these. They'll certainly fill your "I need to feel my abs burn" craving but be careful to keep your total volume of spinal flexion work in check

That's it, try it out and let me know what you think.