The Vertical Body Lever is a great exercise to develop the strength required to perform front levers.
The Vertical Body Lever is one of the very best core exercises. Not only does the Vertical Body Lever work the abs, they also work the scapula, shoulder girdle, and increase the amount of work the lats have to do.
1. Lie down with your arms positioned vertically overhead. Grasp the bar or object you are using with a strong grip. Make sure that the object is stable.
2. Raise your legs and torso off the floor until you are positioned in the candlestick. You should be balancing on your shoulders. The torso and lowerbody completely vertical with the toes pointed. (See Fig. 1)
3. From this vertical position start to lower your whole body down to the floor as slowly and controlled as possible. Keep the body under complete tension and don’t let the hips drop prematurely.
4. As the body is lowering in one solid unit, make sure to keep a strong grip on the supporting object. It will feel like you are trying to pull yourself up. (See Fig. 2)
5. Once your entire body touches the ground you can either relax and then kick up into the candlestick, or try to pull your torso and legs back up in one solid unit. Repeat the movement from point 3.

Vertical Body Lever
Fig. 1

Vertical Body Lever
Fig. 2

All the way through the movement ensure that your glutes, abdominals and lats are all tense. The movement should be smooth and fluid.