The Pistol Squat is one of the most demanding and beneficial lower body exercises around. It will help you to exert power through the entire range of motion.
As with regular squats the pistol squat is an excellent lower body conditioning exercise that will build fantastic posterior chain strength and muscular endurance as well as core conditioning and power. But it is the combination of skills that the exercise develops simultaneously; balance, strength, endurance, flexibility and coordination, that make it one of the most difficult yet important exercises to learn.
You must be able to get full depth on a regular two legged squat before even attempting a pistol squat. By full depth you should be aiming to get your hamstrings to touch your calves. If you can’t do this on a two legged squat do not proceed to attempt a pistol squat until you can. Try to master the Pistol firstly without any weight then bring the kettlebell into your thoughts. Alternate legs after each Pistol Squat.
1. Stand with your feet shoulder width apart. Hold the kettlebell either by the handle or with your hands round the ball with the thumb and first finger around the handle. You can also rack the kettlebell and hold it in this position, though this is much trickier when performing the movement so I recommend you try this after you have once mastered it. (See Fig. 1)
2. Extend one leg out in front and try to steady your balance. Extend your arms so that you are holding the kettlebell out in front and away from the body
3. Sit back onto your heel lowering yourself to the ground, moving your hips backwards as if sitting in a chair. The weight of the kettlebell should counterbalance you sitting back, by pulling you forward slightly keeping your centre of gravity in the right position. Your heel should remain flat on the floor. (See Fig. 2)
4. Descend into the lowest squat possible with your hamstrings touching your calves. Keep the extended leg off the floor. Hold this position for a second to gather your balance and focus. (See Fig.3)
5. Keeping your weight onto your heels, drive the hips upwards fully extending the hip and knee until a lockout is achieved. Repeat the movement from point 3.

Pistol Squat
Fig. 1

Pistol Squat
Fig. 2

Pistol Squat
Fig. 3

To ensure your safety and stability make sure your abdominals are drawn in, and your glutes are tense throughout the full range of motion.