Just what are the best ab exercises?

Recently my neighbourhood had isn't annual curbside cleanup.  Amongst other things it was the good old 'ab rocker' that seemed to be a popular choice to kick to the curb.  If it was solely due to the reason that it didn't deliver the desired results or the fact that it was a dust collector, I will never know, but it did get me questioning what is the most proven exercise for tighter abs?

Now of course we are not naive enough to think that be performing ab exercises alone will get us the results of a six (or eight if you count the 'V') but with the correct nutrition it will definitely be there ready for unearthing. Don't get caught up in thinking if the abs aren't showing then it is a waste of time, because strengthening our abs improves posture, stability, reduces the chance of back pain and a host of other issues

So I set off on my internet travels in search of some, well, research to answer my question.  It didn't take long for me to discover that there is indeed a study for that, which was conducted in May 2012 by the bio mechanics lab at San Diego State University. 

The participants in the study were subjected to complete each exercise 10-12 times, maintaining a two count cadence using electromyograph equipment, while the researchers monitored each participants muscle activity.  The upper, middle and lower (rectus) abdominus plus the hip flexors (to attain if the exercise was being performed correctly) were all under scrutiny to see which exercise rated the highest in muscular activity. It was found that the exercises which required constant muscular contraction mixed with body rotation fared the best.

Here's the list (a good guide is to try and complete 20 of each exercise)

1.  Bicycle legs - laying on the floor making sure your lower back is pressing into the mat.  With your hands behind you head, (without relying on your hands too much) keep your chin tucked, turn on abs and bring knees up to about 45 degree angle and slowly go through the bicycle motion. Alternate elbow to opposite knee, remembering relaxed breathing throughout.

2. Captains chair- not shown equipment found at a gym

3. Crunch on exercise ball - with your feet flat on the floor, sit on the ball and let it roll back slowly so that you are resting on your middle back. With arms crossed over chest and chin tucked, contract your abs raising your torso to no more than 45 degrees. The wider the feet the easier it is.

4. Vertical leg crunch - Again flat on the mat, hands behind your head for support, with your legs straight up in the air and crossed at the ankle.  Keeping your neck muscles relaxed aim to lift your torso towards your knees

5. Torso track - not shown equipment from a gym (personally I am not fond of this one as it can lead to lower back pain)

6.  Long arm crunch - On your back, extend the arms straight our beside your ears with hands on top of each other.  While contracting the abs and keeping chin tucked, lift your shoulder blades off the floor keeping the arms straight.

7. Reverse crunch - Another back on mat exercise but this time with hands on floor beside your body.  Lift the knees, bending them to 90 degree and curl the hips off the floor using your abs. Keeping a steady rate, lower and repeat.

8. Crunch with heel push - Same as the basic crunch but by digging your heels into the mat at the top of the crunch while slightly raising your glutes off the floor it activates the lower abs better

9.  AB roller - done with a swiss ball, kneel in front of the ball and place hands parallel.  Keeping your hip and back straight roll the ball out until you feel the abs engage (don't overdo it!) and return by pushing into the ball.

10. Hover or plank - With forearms on the floor press up into a flat back position on the toes.  Keep the bum and hips down, shoulders away from ears and so that you are in line from head to toe.  Hold for 30-60 sec and repeat 3-5 times.

What was interesting to note that the traditional crunch came in at 11th spot and wait for it, the ab rocker came in at 13th!  Of course these results are all based on traditional ab exercises and I think it would be interesting to see how they stack up against pilates or cross-fit style abdominal techniques.