Using CCK or Taxonomy with Custom Fields in Drupal 7
My idea: make CCK fields of all personal data you want to collect about the athletes. (length, weight, ...) These are different for every athlete.

When you have items that are similar, you should use taxonomy. (Type: Soccer player, Golfer, ...)

Using both taxonomy and CCK makes a complex but great system!

*An example:

I'm making a "travel" website about Spain. A website with many pages.

On my website about Spain I have a regio related page. This page shows content about cities, golf tracks, parks, ... It has an image on top (CCK field), a "tag" (taxonomy term to link pages - show list with simmilar content), a "regio tag" (also taxonomy list of all regio's) and two text fields: positive / negative (CCK fields to enter good and bad things about this city / track / park and so on.

The image and positive/negative fields are for all pages different. The "regio tag" can be the same for some pages (same with the tag).

This way you easily make a view with similar pages people can visit!*