Lateral Squats
Lateral Squats work many of the same muscles as a Split Squat or a Lunge, but in a lateral motion rather than straight forward. It’s a solid lower body pushing exercise you can mix into your program for a different challenge.
Setup
Take a wide stance with one foot slightly forward of the other. I like to line up the arch of my front foot with the toes of my back foot to make sure I always get into the same position.
Execution
Sit down and back into the side of the front foot. You should aim to get your hip and knee aligned so your thigh is just about parallel to the floor, but you might need to do some mobility work for your calves and inner thighs to get full range of motion. Keep your torso as upright as you can so that the line of your spine is parallel to your shin, or slightly more upright.
For the body weight version you can keep your hands on your hips or reach out with each repetition. 
Make it more challenging by adding resistance with dumbbells or a kettlebell.
How much and how often
Start conservatively to minimize post workout soreness; one set of 6-10 repetitions on each leg is a good place to start. If you tolerate that well, try two sets, then three sets in subsequent workouts. To increase strength, stay within the 6-10 repetition range and use challenging weights. If muscle endurance is your goal, do between 12 and 20 repetitions per set.
Like all strength training exercises include Lateral Squats in your program 2 to 3 days per week on non-consecutive days.
