Specificity - the SAID Principle

In 2000 I wrote, published and claimed copyright on this concept (bolding added now):

The principle of specificity suggests that your adaptation to training will be very specific to the nature of the training you are doing. For example if you are doing a number of long, slow jogs per week, your physical capacity to do that specific activity may be enhanced. An acronym that appears to have lost popularity but is quite illustrative of this point is the SAID Principle - specific adaptations to imposed demands.

I was conducting research and I came upon the following exercise in a publication copyright claimed by another 'author' at a subsequent date (bolding added):

The SAID principle – specific adaptation to imposed demand. This principle suggest that your adaptation to training will be specific – e.g. long slow running will enhance your ability to run long and slow – but is unlikely to enhance your ability to run short and explosively.

And I said to myself: “That looks familiar!” So I cross-referenced it and I said to myself: “Wow! No wonder that looked familiar!”

And I came upon this wording another one more times by the same 'author' in different publications - in the absence of credits or references to the origin or permission to use from the original author (myself), and that the 'author' claimed copyright....