In one of his least popular moves, the President of the University of Colorado spent $780k to establish the "brand" and naming specifications.
http://www.dailycamera.com/ci_17152265
The approved way to refer to the University where Mark Wetmore coaches track/cross country is:
University of Colorado Boulder
see
http://brand.colorado.edu/resources/faqs
The lack of punctuation or "at" is similar to that of the University of California system.
Informally many people refer to CU, but it is indeed not normal to say Colorado University or UC. Rationale reasons for this practice remain obscure. see
http://www.cubuffs.com/ViewArticle.dbml?DB_OEM_ID=600&ATCLID=28035
To answer the first poster's question, there are no running requirements to be accepted as a STUDENT at the University of Colorado Boulder.
Here are the modest academic requirement guidelines.
http://www.colorado.edu/admissions/undergraduate/apply/freshman/admissioncriteria