Useful for anyone that wants to do plyo work.
NICE! Wanted to build a small-med on for step ups and deficit deadlifts, was afraid to assuming it would crumble with me and the weight on it, gonna check this out.
Some people use 2x4 to reinforce the inside. Personally I think 3/4 inch plywood is plenty strong enough with the screws in it, I mean it is often used as subfloor we walk on and the box distance is as small as where your joists would be. but can see why some feel more comfortable with the 2x4 bracing.