when i started crossfit last july, my box jump was a whopping 3 or 4" (the height of a 45-lb. plate). and that 3 or 4" was rough. took everything out of me. over the months i have slowly improved, adding more height to my stack of weights, always looking on with envy to those who were using the actual box.
well, this morning i finally joined my fellow crossfitters at the box by jumping on the box. that's right. an 18" box jump.
like a boss.