Which type of contraction occurs when the muscle force exceeds the resistance?

The situation described in the question refers to a contraction type where the muscle force is greater than the opposing load, resulting in movement. Isotonic contraction is the correct answer because it involves the muscle shortening (concentric contraction) or lengthening (eccentric contraction) while maintaining a constant tension throughout the movement.

In an isotonic contraction, when the muscle generates sufficient force to overcome the resistance, it either lifts a weight or moves a part of the body through a range of motion. This process allows for dynamic movement, such as lifting a dumbbell or doing a squat.

The other types of contractions do not align with the scenario presented. Isometric contractions maintain the muscle length without movement despite force generation, while isokinetic contractions involve movement at a constant speed with varying resistance. Eccentric contractions occur when the muscle elongates under tension, typically resisting force—not when the muscle force exceeds it. Understanding these distinctions is vital in applying the correct concepts within fitness and personal training.