According to AShotofAdrenaline.net, the squat thrust mainly works several muscles in the legs. The muscles in the legs particularly stressed by squat thrusts are the quadriceps, hamstrings and gluteus maximus. Aside from this, squat thrusts also improve cardiovascular health.
According to the Washington Post, because the squat thrust combines two of the most effective body weight activities, a squat and a push-up, it is an overall body strength exercise that, when done in a fluid motion repeatedly, is bound to leave the exerciser out of breath in a matter of seconds. Because of this, it is a mainstay of personal fitness regimens, martial art classes and boot camps. Starting from a standing position, execution of a squat thrust involves moving to a squat, thrusting both legs back to a push-up position, doing one push-up, jumping back to the squat position and executing a vertical jump with hands outstretched.
According to ChoosingtheHealthyWay.com, the squat thrust, also known as the "burpee," was originally a military drill exercise used as a punishment or as a test of endurance and strength. As it is such a challenging exercise, beginners can take certain steps to make the squat thrust less strenuous, such as stepping back from the push-up position one leg at a time.