Crossfit is massive nowadays and growing!
Due to the Crossfitter's aim to keep their training programs constantly varied with
high intensity functional movement many of them tend to use easily accessible training gear such as
sandbags,
DIY medicine balls and the like.
There have been a few builds on DIYSTRENGTHGEAR via the Crossfit population, one of them being the
DIY Crossfit Glute Ham Raise (I have some plans of my own to build one very soon)
One definite 'must have' piece of training equipment is the
Plyometric Box. I have one box that I made years ago for DIY purposes and have since used for many different training applications from plyometrics to dumbbell training.
If you are thinking of making your own PLYO BOX then look no further than this
superb PDF plan that will explain in great detail with dimensions how to build one identical to the one in the picture.