Concentric muscle action occurs when a muscle generates sufficient tension to overcome resistance, resulting in the shortening of the muscle fibers as it contracts. In the traditional gym environment, this is recognized as the “lifting” or “positive” phase of a repetition—such as the upward motion of a squat or the pulling phase of a row. For an endurance athlete, understanding concentric movement is vital because it is the primary driver of propulsion. While eccentric (lengthening) movements often cause the structural micro-tears associated with soreness, concentric actions are focused on power production and mechanical efficiency, offering a way to build strength and joint resilience with a lower “recovery tax” on the muscular system.
Outside of the weight room, concentric contractions are the engine of every endurance discipline. In cycling, the downward power phase of the pedal stroke is a dominant concentric action, as the quadriceps and glutes shorten to drive the crank arm. In the washing machine of a mass swim start, the “catch and pull” phase—where the latissimus dorsi and pectorals shorten to move the body forward through the water—is a pure concentric effort. For runners, the “toe-off” phase, where the calves and hamstrings contract to propel the body upward and forward, represents the critical concentric moment that determines stride power and speed.
Integrating focused concentric training into a periodized plan can significantly enhance an athlete’s performance. By emphasizing the shortening phase of a movement, athletes can improve neuromuscular recruitment and “toughen” the connective tissues without the excessive eccentric loading that might compromise a high-volume week of sport-specific training. Whether you are navigating a steep climb or sprinting for the finish of a race, your concentric power is what translates metabolic energy into forward motion.
