This article reports data concerning the Internet-related activities and interest for Ironman Triathlon competition. Google Trends (GT) was used and mined from 2004 onwards. The interest for Ironman Triathlon was found to be cyclic over time. The Triathlon-related Internet activities negatively correlated with the number of finishers per year (Pearson׳s correlation r=−0.690, p-value<0.05), while an increasing participation of female athletes who were less likely to surf the Internet could be noticed (r=−0.811, p-value<0.05). Further, younger athletes, who were more likely to access the web, were underrepresented in the Ironman Triathlon event. Moreover, there was a correlation between the biking time and the Internet query volumes (r=0.590, p-value<0.05), and, in particular, for the male athletes (r=0.664, p-value<0.05). Finally, the countries which most contributed to the Internet query volumes were those with the highest number of medals.
