During a 100m sprint, what percentage of energy contribution comes from the anaerobic system?

The correct answer reflects that the anaerobic energy system is predominantly utilized during short, high-intensity activities such as a 100m sprint. The anaerobic system encompasses both the ATP-PC system (phosphagen system) and anaerobic glycolysis, which are key sources of energy for activities lasting from a few seconds to around two minutes.

During a 100m sprint, which typically takes around 10 seconds for elite athletes, the body's demand for instant energy far exceeds what can be supplied through aerobic pathways, which take longer to ramp up and provide oxygen-dependent energy. Thus, nearly all energy for this short duration of intense exertion comes from the anaerobic pathways, making it about 90% to 100% anaerobic contribution in an elite sprint setting.

The high percentage reflects the intense nature of the effort, as the anaerobic system rapidly produces ATP while avoiding the slower oxidative processes that come into play during longer-duration, lower-intensity events. This is why a response indicating 90% is most accurate, aligning with how athletes tap aggressively into the anaerobic system for maximal performance in short sprints.