The alactic anaerobic energy system (also known at the ATP-CP system) is the most immediate energy available to the muscles. It uses ATP-CP already stored in the muscles. At 100% output, there is about 7 seconds worth of energy available. At less than 100%, this system lasts up to 40 seconds. Recovery is 5-10 times the work. A 6 second sprint would require a 1 minute recovery.