Final answer:
The correct regression for a client struggling to maintain form during tuck jump exercises is to decrease the intensity, which could include lowering jump heights or performing the exercise more slowly.
Step-by-step explanation:
When a client is having trouble maintaining form during a tuck jump exercise, it is important to adjust the exercise to prioritize correct technique and safety. In this case, the appropriate regression would be to decrease the intensity of the exercise. High-intensity exercises can be difficult to perform with proper form, especially when fatigue sets in, and maintaining form is crucial to prevent injury and ensure that the client is targeting the appropriate muscle groups. Reducing the intensity can involve modifications such as lower jump heights, performing the tuck jump at a slower pace, or switching to a less challenging plyometric exercise.