9.5K views · 227 reactions | The thruster requires a long line of action against the normal force of gravity with a load plus body weight, creating one of the most profound accelerations possible. The movement works from full flexion to full extension at the ankle, knee, hip, shoulder, and arm, and involves most of the major muscle groups. These factors earn the thruster its reputation as "the most draining of all exercises." #crossfit | CrossFit | Facebook