1. Establishing Target (THR) & Resting Heart States (RHR) By Professor Engle 2010 Karvonen Method reference c/o wikiHow the how to manual that you can edit retrieved from http://www.wikihow.com/Calculate-Your-Target-Heart-Rate Definitive listing c/o Heart rate. (2010, April 9). In Wikipedia, The Free Encyclopedia . Retrieved April 13, 2010, from http://en.wikipedia.org/w/index.php?title=Heart_rate&oldid=354975875