What is one effect of changing lever lengths during exercise?

Changing lever lengths during exercise primarily impacts the mechanics of movement, particularly by reducing resistance. When the lever arm—the distance from the axis of rotation (such as a joint) to the point of resistance (like the weight being lifted)—is modified, it can change how much effort is required to perform a movement. A shorter lever arm generally means the muscles have to exert less force to overcome the same amount of resistance, making exercises easier and potentially allowing for greater range of motion or more reps with the same weight.

The adjustment of lever lengths can affect the way forces are applied in exercises, subsequently influencing the effectiveness of strength training by allowing individuals to target specific muscle groups more effectively. While the other options—such as heart rate, flexibility, and endurance—can be influenced by various training variables, they are not directly affected by altering lever lengths in the same way that resistance is impacted.