The alactacid energy system also known as the ATP/PC system is the Ferrari of the energy systems. 
It has all the glamour of the 100m sprint and provides the energy used for power and strength. This system has lots of power, but uses its fuel without care. When used flat out it lasts no more than 8 seconds, not even enough for Usain Bolt to complete 100m in his world record time (9.58).
When studying this system it is good to attach it to an event, like the 100m sprint or shot-put. This will help you remember some of the details needed for your exams. This system has no waste products and produces ATP at a very fast pace, which allows Usain to accelerate powerfully and move at great speeds. Its fuel source is the muscular stores of PC, which react with ADP to produce more ATP. When these stores run out fatigue sets in and the lactic acid energy system is used for the last 1.58 seconds of this race. This system recovers quickly requiring roughly 1 min. The only by product is heat, which Usain has plenty of.
