Final answer:
Isotonic exercises involve muscle length changes during contraction to produce movement, characterized by constant tension through concentric or eccentric contractions, in contrast to isometric contractions, which increase muscle tension without length changes.
Step-by-step explanation:
Isotonic (dynamic) exercises are those where the muscle changes length to produce muscle contraction and active movement. In isotonic contractions, the tension in the muscle stays constant as the muscle actively shortens or lengthens to move a load. This can be divided into two categories: concentric contractions and eccentric contractions. During concentric contractions, the muscle fibers shorten as they exert force, such as lifting a weight upwards. Eccentric contractions occur when the muscle fibers lengthen while controlling the movement of a load, such as lowering a weight carefully.
Comparatively, isometric contractions involve an increase in muscle tension without a change in muscle length, and they are important for maintaining posture and stability. Understanding these concepts is crucial for designing effective exercise regimes that utilize both types of muscle contractions, resulting in a comprehensive fitness program.