How does one train legs to become gradually stronger without any equipment? See the 10 levels of bodyweight squats below, beginner to beast, starting with:
level 1: jackknife squats
Placing your hands on a sturdy knee-high object will take away part of the resistance, making this a great exercise for people recovering after an injury, very deconditioned or overweight trainees. Keep your feet at a comfortable position roughly hip-distance apart (this will vary slightly from person to person) and your back relatively straight as you squat down as low as possible. Your heels should be touching the ground throughout the entire movement, if that’s not possible, go as low as you can without lifting them up. It is recommended to do some form of stretching or mobility work alongside all of these squat progressions, even though jackknife squats themselves are a great mobility exercises for the lower back and hips.
Execute them slowly and controlled (2-4 sec down, 2-4 sec up), you can pause at the bottom position for a couple of seconds, remember that doing less with good form is always better than more with bad form!
level 2: supported squats
Another beginner’s progression, which can be used to increase mobility, speed up recovery after an injury and help build some initial strength in the lower body.
Take hold of a sturdy object at hip-height and use it to support yourself throughout the movement. Slowly and with control squat down as low as you can whilst keeping your heels on the ground and your back straight. You can hold it at the bottom position for a moment, then extend your legs, push against the ground, whilst supporting yourself with your arms. Make sure most of the work is done by your legs, not your arms! Pull yourself up the least you can, until you become able to squat without any support.
level 3: full squat
Most people who have done some sort of training or peaked into a fitness/circuit class are going to be familiar with this one. It’s also the progression most of you will begin with. Start the exercise by standing tall, feet roughly hip-distance apart. Whether your toes are going to aim forwards or a bit outwards depends on how you are built, it will vary from person to person. From there lower yourself down to the lowest point you can get, with the majority of your weight on your heels. Don’t lean with your upper body too much forwards, as it puts unnecessary pressure on your lower back. Push against the ground from the bottom position and return into a standing position.
If you can’t do the full range of motion due to lack of strength and/or flexibility, do not despair! That’s what the intermediate levels between each progression are for – partial reps (half and quarter repetitions) and slow negative reps (where you perform only the eccentric phase of the movement, in other words lowering yourself down into the bottom position). But before you try any of these make sure you can do a decent amount supported Squats, the previous progression.
And as always… Stretch!
level 4: close squat
This progression is going to train your legs in a slightly different angle than the previous Full Squats, which makes it more challenging. But you’ll get rewarded with improved mobility and strength to move forwards and get better.
Start from a standing position, but this time your feet are not more than an inch apart. Lower yourself down in a controlled manner, not leaning forwards excessively, back straight, go ass-to-grass. If you can’t go all the way down, work on your mobility and use the intermediate levels – partial and negative reps.
Be consistent with your training and remember, what’s kicking your ass right now, will soon become your warm up!
level 5: archer squat
Get ready for a big upgrade! This type of squats, also known as Cossack squats, will significantly improve your flexibility, your strength and engage the inner part of your thighs more than any other exercise.
Begin standing upright, feet wide apart. Descend shifting your weight on one leg, whilst keeping the other leg straight. The position of your arms matters more than it did with previous progressions – keep them extended in front of your body as a counterbalance. Rounding your back at the bottom position is natural, but avoid slouching. Push down with the bent leg to return into the starting position, then perform the squat on the other leg.
There are two ways of doing it: with the toes of one foot pointing up and with both feet touching the ground throughout the entire movement. Challenge yourself and master both!
level 6: supported pistol squats
Variation a) 
Variation b) 
Now we’re in one-legged squat territory, which means you are going to have great strength, flexibility, but also balance once you master the pistol squats and the steps leading up to it.
Variation a) Hold on to something sturdy you know won’t move. Lift one leg up and keep it straight throughout the movement, then lower yourself down as low as you can manage without lifting your heel up. Your back is going to round up slightly, but make sure you are not slouching. Push against the ground and assume the starting position.
Variation b) This one is more challenging than the previous variation, because you are supporting yourself only at the bottom half of the movement.
Stand next to a bench, chair, or bed, arms extended in front of you, one leg raised up. Lower yourself down and place one
hand on the object you are using for support. Push against the object you are standing on to get back up into the initial position.
level 7: elevated pistol squats
Step up on the edge of a mounted bench or heavy box, stand tall and raise your arms in front of your body for balance. Squat as low as possible with the heel on the bench, whilst the front leg remains more or less vertical. Not having to hold the leg horizontally at the bottom position will make it easier for you, so good luck!
level 8: pistol squat
The perfect leg exercise! Builds strength in one’s lower back, gluteus, quads, hamstrings and calves as well as hip flexor thanks to holding the other leg horizontally, improves balance and mobility.
Stand upright with your hands extended in front of your body for balance and one leg raised up (the higher the more difficult it will become to squat). Push your hips backwards and bend into a squat, whilst keeping the front leg horizontal and off the ground. Use only the standing leg to get back up into the initial position.
level 9: Pistol Squats with hands behind your back
The technique for this exercise is the same as for a standard pistol squat (see post from two days ago) but there’s one difference – your arms are behind your head. That means you can’t use them as a counterbalance, which makes it more challenging. Give it a go!
level 10: Pistol Squats with hands behind your back
Congratulations, you have reached the Master Level of the squat progression! Up until the previous one you were using your arms to help you execute the movement and stay balanced, but now they are going to work against you.
Holding your hands behind your back is a small change to the pistol squat, but it makes a huge difference! When I first tried this variation I was able to do 10, or nearly 10 normal pistol squats. It really caught me by surprise when I wasn’t able to lift myself up!
As you lower yourself down, hands behind your back, you will naturally lean more forwards than whilst doing a regular pistol squat. The first bit of getting up is the hardest one, but once you are past it, you won!
Being able to do 5 or more Pistol squats with hands behind your neck is a must if you want master this type of squat. Just as before, start of with negative reps, then partial reps and eventually you will manage the full range of motion!