During the "frog" exercise, what is the effect of higher resistance?

In the "frog" exercise, using higher resistance primarily emphasizes the quadriceps muscles. As the resistance increases, the quadriceps are required to work harder to extend and flex the knees, which is a fundamental movement in this exercise. This focus on the quadriceps helps to develop strength and endurance in those muscles, making them more dominant in the movement.

The core engagement does increase with resistance, but it is not the primary focus of this specific exercise. Similarly, while enhanced lower back strength and flexibility can be byproducts of various Pilates exercises, they are not the direct effects of increased resistance during the "frog." Thus, the main outcome of higher resistance in this context is indeed the increased activation and use of the quadriceps muscles.