Up and overs are a great cardio move that can be done with a step. It’s a great move, because there are at least three possible modifications to help increase your calorie burn. The easiest version is just shuffling from side to side while alternating which foot is on top of the step. Even though it’s the easiest modification, it still presents a decent challenge. You have to maintain a strong core to not slip off of the bench.
The next version involves jumping over the bench with both feet while holding onto the bench with both hands. This is much higher impact than the first, so I wouldn’t recommend it to anyone with knee or ankle problems. It’s also involves some more stabilization through your upper body as well as your core. It’s important to land solidly and not too heavily so I’d say it involves much more finesse.
The last version is also the hardest of the three. Although I did the same number of reps of each version, this one left me the most winded and took the longest. It’s basically the same as the second version but with an additional hop onto the step with both feet. I would not recommend trying this modification unless your very confident in your ability to stick the landing on top of the box. It would be far to easy to slip and severely twist your ankle.