Sprinting, it's a love - hate thing. The pain during a 100% full throttle sprint is deep and your mindset plays a huge part in your ability to tolerate the suffering. What's funny is in some twisted way that raw painful effort is somehow satisfying or even addictive in a bizarre sense.
But what actually propels your body in that effort, what variations does it go through to sustain that power? Pure sprints last from just a couple of seconds to around 30 and a number of compounds or chemical reactions occur in a very short time. The initial 1 or 2 seconds you utilize ATP (Adenosine Triphosphate) which is a high energy compound which runs out quickly. After that and until around 10 seconds into the effort your body switches compounds to creatine phosphate to produce more ATP. Beyond this point ATP is produced by the breakdown of carbs using a process known as glycolysis. Then in turn produces pyruvate. During aggressive sprinting the pyruvate is then broken down into lactate and the burn begins. During this whole process energy is created without the need for oxygen or anaerobically. The last thing you’re thinking about during those hell bent all out sprints is these energy systems but it's kind of amazing what's keeps your body going in such a short amount of time.