The general rule of thumb with step-ups is height before load: determine the appropriate height first, then choose an appropriate load to accomplish the reps you plan to perform.

With the side step-up in particular, the maximum height is determined by how far forward you can move the working knee, or put simply, how much calf flexibility you have.

The more you’re able to move the knee over your toes, the more vertical you’re able to keep the trunk, and the higher the step can be. The key is to keep the hips level throughout the movement. If your hips dip down to one side, the step is too high.

The height will range from 4 inches to 11 inches – anything above that is usually too high.

In the video, I’m demonstrating back side step-ups with the third step height on the Atlantis Leg Platform, which is 11 inches from the floor. Notice how my knee goes past my toes but the heel always stays down on the platform, and there’s no push-off from the opposite foot.

Learn everything you need to know about this staple exercise in Step-Ups Develop Muscular Legs.