What is the primary adjustment instructors can make to control workout intensity?

The primary adjustment instructors can make to control workout intensity is to change the level of weights used. Adjusting weights directly impacts muscle engagement and the overall demand placed on the body during resistance training. Using heavier weights will increase intensity by requiring the muscles to exert more effort to perform the same exercises, while lighter weights can reduce intensity, making it more accessible for participants with varying fitness levels.

While increasing the number of repetitions and altering the duration of rest periods can also affect intensity, these methods may not be as direct or immediate in their effect on the exertion level compared to weight changes. Adjusting the lever arm length does influence mechanical advantage and could alter the difficulty of certain movements, but it is not as commonly used to modify intensity as changing weights. Thus, the selection of appropriate weights remains the foundational method for managing workout intensity effectively in a group fitness setting.