Squats primarily target the legs, a large muscle group, stimulating muscle growth in the whole body. Squats also work almost every muscle at the same time, engaging legs to handle the weight, the core to stabilize the trunk and every other muscle to help the torso maintain balance. Squats build power and mobility and prevent injury.  All versions work the glutes, hamstrings, quadriceps, hip flexors and calves. Performing squats can help correct numerous imbalances like weak glutes or a hunched back. They are an INCREDIBLE exercise for people who have desk jobs and sit most of the day, helping to reverse those effects. Other benefits include reduced cellulite (improved circulation), improved digestion and posture, stronger joints and improved flexibility. 

Chair Squat

Differentiators/benefits:

• Targets quads more than other types of squats
• Narrow feet width also targets outer thighs (where saddle bags live)
• Strengthens ankles, thighs, calves, and spine
• Stimulates the abdominal organs, diaphragm, and heart 
• Reduces flat feet 

Cueing: Walk feet narrower than hip width apart, only a few inches apart (this is very important, especially with the ball, because clients are squatting at hip height or wider). Root into heels and inhale as you sit back like you’re sitting in a chair, making sure knees are directly over ankles and not beyond them. *Upper body placement will depend on which type of chair you’re doing, but always cue tight core, straight back and lifted gaze. 

Types in class:

• Upright chair (at barre, can place ball between legs, can add power)
• Incline chair (at barre or using TRX, can place ball between legs, can add power)
• Reverse chair (with ball between upper back and barre, can add power)
• Warm up and combo chair (chair squat plyos, chair squat with reverse leg lift, chair squat in center of room with tricep weight work, etc.) 

Sumo Squat

Differentiators/benefits:

• Works more into glutes, low back and hamstrings than other types of squats
• Lifts glutes
• Increases mobility and functional strength

Cueing: Walk feet SLIGHTLY wider than hip width apart, angling out at 11 and 1 (make sure clients don’t go too wide into a plie). Inhale as you hinge forward at hips, dropping tailbone low. Root into your heels and make sure knees stay above ankles. Tighten your core and lifting your chest to protect your back. *Arm cueing will differ depending on which sumo you are doing. 

Types in class:

• Incline sumo (at barre or using TRX, can add power)
• Reverse sumo (with ball between upper back and barre, can add power)
• In center of room (ball in hands, can add power), works more into lower back, glutes and hamstrings
• Warm up and combo sumo (side step sumo with arms/weights, sumo with reach behind, etc.)

Plie Squat

Differentiators/benefits:

• Targets glutes and inner thigh adductors more-so than a regular squat 
• Creates longer, leaner legs
• Boosts flexibility significantly (especially in hips) 

Cueing: Step feet into a wide stance, turned out at 10 and 2. Bend your knees, inhale as you sink down and hold. Make sure knees are pressed wide and directly over ankles. *Upper body placement will depend on which type of plie you’re doing, but always cue tight core, straight back and lifted gaze. 

Types in class (there is no reverse plie):

• Incline plie (at barre)
• Upright plie (in center of room or at barre, can use ball, can add power)
• Warm up or combo plie (with weights, side stepping, plyos, etc.) 

Links below: 

http://www.fitnessandpower.com/training/workout-routines/sumo-squat-vs-regular-squat 

http://www.healthydietbase.com/sumo-squat-the-best-exercise-to-tone-and-shape-the-glutes/

http://www.stbotanica.com/blog/how-to-do-plie-squat-exercises/