Plyo boxes are used in plyometric workouts. A plyometric workouts quickly expand and contract muscles to improve performance, most often in sports. A plyo box bought in a retail store can take a chunk out of your wallet, but you can save money and build your own plyo box.
Cut the pine studs into eight 2-foot pieces, four 1 ½-foot pieces and four pieces to use as cross braces. (You might want to build the box first and cut the cross brace pieces later.)
With four of the 2-foot pieces make a square and wood glue them together. Then screw them together with wood screws. Repeat with the other four pieces.
Put the 1 ½-foot pieces in each corner of one of your squares standing up. Glue and screw.
Tip the square with the 1 1/2-foot pieces on its side and slide the other square over the vertical 1 ½-foot pieces. Glue and screw the second square to the vertical pieces so it looks the same as the bottom square.
Stand the box back up on the bottom square. Put in the cross bracing. The easiest way to do this is to place a piece of 2-by-4 across the box diagonally, mark the place to cut, then cut it. After you cut a piece glue and screw it onto the box and move onto the next piece. Make sure the cross bracing on facing sides is going in opposite directions.
Place the plyo box top down on the plywood and trace before you make your cut. Cut the shape out of the plywood and glue it to the top of the box. Place screws in the corners.