Quadriceps contractions during L-sit

Since I've moved onto the full L sit, I've noticed that I can't keep my legs absolutely straight, without bend. If they're straight, like after 2 seconds in the Lsit, my quadriceps on both legs are starting to contract like hell, it is painful, and it's almost like a muscle spasm, or something like that (I don't know the exact term for that painful muscle contraction in english).

I don't know if this is a strenght or flexibility issue, but I surely can hold low Lsit for a long time, and it seems that my legs, not core, are working in the Lsit. :roll:

Tips and comments appreciated.

Sounds like muscle cramps. Don't worry about them too much, as you continue to get stronger they will stop. Some light massage can help a little, but it will get better with time and practice.

It sounds like your hamstrings might be too tight. Your quads need to contract more to pull against your tight hamstrings. Try stretching your hamstrings before doing an L-Sit.

...and don't forget to drink enough water, by the way, especially if you're supplementing.

As said, your quads will adapt, don't worry about that.

Work your pike straight legs etc..

PS : toes pointed during L-sit.