Three standards define the CrossFit view of fitness. The first is based on the ten general physical skills widely recognized by exercise physiologists. The second standard, or model, is based on the performance of athletic tasks (performing well at any and every task imaginable). The third is based on the energy systems that drive all human action (the three metabolic pathways)

Free Choice/Make-up Use this time: a) to make up for another day's workout (Monday/Tuesday/Wednesday); b) to practice skills and movements like Olympic lifts, double-unders, and handstands; c) to work on strength training; d) to train your endurance with some running/rowing; e) or all of the above!