As I have outlined in the article 3 Steps to Develop your own Power Training Method that Power is effectively trained with short durations due to the high involvement of the PhosphagenSystem / ATP - CP energy sSystem / ATP - CP energy systemsystem.
This ATP, delivered through what is known as our creatine phosphate (CP or phosphagen) system, gives us enough energy for immediate but very short bursts of activity lasting just a few seconds.