Most plyometric training focuses on bilateral, vertical exercises (nothing necessarily wrong with that). We hop and jump with two feet, in a mostly vertical plane (straight up).
Adding unilateral, horizontal, and lateral plyometric exercises is a great way to accelerate the development of explosive power, balance, and muscular endurance, according to multiple studies in the Journal of Strength and Conditioning Research.
It’s pretty simple to incorporate unilateral (single-leg), horizontal (forward), and lateral (side-to-side) plyometric exercises into your training, once you’ve become comfortable and proficient with more traditional plyometric exercises.
When performing unilateral plyometric exercises, it’s important to start with a low intensity level and degree of difficulty.
If you’re already doing bilateral, vertical hops and jumps as part of your training, try adding single-leg vertical, lateral, and forward hops and jumps to your routine, on flat ground. As your strength and balance improves, add low hurdles and plyo boxes to the mix.