H-index and number of citations The H-index is a measure based on the number of citations of the publications of an author at a specific time.A high H-index speaks for a large scientific influence of the author in question. The H-index of an author can not sink over time and actually only increase.You can calculate the H-index yourself or look in Web of Science, Sopus or Google Scholar.However, each source calculates the H-index otherwise so that the value is not quite comparable.Google Scholar is accessible to every human being. For me, the number of quotations are currently on 3226 and the H-index to 27. The work ‘Fat Oxidation in Men and Women Endurance Athletes in Running and Cycling’ in Int J Sports Med. 2004 Jan; 25 (1): 38-44 was most mentioned with 109 citations. Followed this work from ‘Participation and Performance Trends in Ultra Triathlon from 1985 to 2009’ in Scand J Med Sci Sports.2011 Dec; 21 (6): E82-90 The 75 times quoted. The last top ten publication is ‘Upper arm circumference is associated with race performance in ultra-endurance runners‘ in Br J Sports Med. 2008 Apr;42(4):295-9.