The L-Sit is a fancy Calisthenics exercise that activates all body muscles. Mastering the L-Sit is not an easy task, yet it is doable if you persevere training the exercises that lead to it.
The L-Sit is a full body exercise, activating all of upper body, core and leg muscles. Shoulders and triceps are pushed, abs get stronger, quads and hip-flexors are pushed to the limit, and holding the position even if for a few seconds, is a great exercise.
The position is also nice to watch. For this you will see gymnastics and circus athletes performing it. Nobody stays indifferent, when facing someone in an L-Sit position.
Prepare your hamstrings and core. Repeat until you can sit down and hold 60secs in a perfect L Sit position.
Sitting in a perfect L Sit position activates core and hamstrings. This position can be challenging to hold for a single minute, if you do it in the perfect form.
Strengthen your shoulders. Hold this position for one minute in a row. Initially, achieve this using multiple sets, such as 6x10, then 4x15, then 3x20.
Exercise is great for the shoulders, and a preparation for L Sit.
Work on an easy version, one leg at the time. Aim for 60 seconds in total, 30 for each leg.
The Tuck position fully activates all core muscles for the L Sit. Ain 60 seconds in a row.
Exercise is a preparation for the Floor L Sit. It requires strong shoulders and abs, although other muscles are also involved.
Next step would be to have a perfect position in one leg. Ensure is fully straight and horizontal, or even feet higher than hips. Aim for 60 seconds in a row, 30 for each leg.
Easier than the L Sit, yet demanding, extend one leg from the tuck position involves the same muscles. See it as an intermediate exercise, while practicing toward the L Sit.
Finally, execute the L Sit keeping your legs fully horizontal, or feet higher than the hips.
A complete exercise working many muscles.
There are other progressions available.