Our power training starts when we learn how to practice the 3-Count.

This simple training tool teaches a few important controls that are relevant to the topics of classical mechanics viz velocity, acceleration and momentum. A more detailed explanation is on page 58-59, TaijiKinesis Vol 2 : Learning the Taijiquan Form.

The video below shows the relevance of the 3-Count in increasing the power of a strike by controlling momentum.