Core training - planks vs. L-sits?

Question

Does the L-sit:

overlap with the plank:

or do these two exercises complement each other well? Is there any benefit to holding planks that can't be obtained by holding L-sits?

Answer 1

Both exercises have some overlap in terms of the muscles used, particularly internal abdominal muscles (if you maintain good posture in the plank), but I would say that they are significantly different exercises and both worth practising in their own right. In fact, beyond being static positions and involving abdominal contraction they are rather dissimilar.

I would consider the L-sit to be a harder exercise than the plank. Certainly most people can hold a plank for much longer (with a little practice) than an L-sit. For example, I have held a plank for just over 8 minutes, but would struggle to hold an proper L-sit for more than 15-20 seconds. That said maintaining a really good hollow bodied plank, with tight glutes and lower abdominals is challenging.

Here are some key differences between the two exercises:

• They both involve an antagonistic contraction of muscles of the back and abdomen to maintain good posture, but in the plank the effort is distributed more widely across the abdomen and lower back, whereas the L-sit is heavily lower abdominal with perhaps broader involvement of the back (to 'push the bum back').
• In the L-sit the quadriceps and hip flexors are strongly engaged to keep the legs straight, furthermore hip flexor and hamstring flexibility are quite important to avoid rounding of the lower back around the sacrum and maintaining straight legs, respectively. Their involvement, particularly of the leg muscles, is much less in the plank.
• The shoulder and triceps support needed for the L-sit can be quite challenging to maintain balance, whereas with properly positioned elbows the arms are less likely to fatigue first in the plank.

You might want to work progressions of the plank such as: http://gymnasticswod.com/content/v-out (very hard, I find). The L-sit should help with leg position in somersaults, and the plank or rather a self-supporting hollow body position is very fundamental throughout gymnastics.