Age, sex and (the) race: gender and geriatrics in the ultra-endurance age.

Ultra-endurance challenges were once the stuff of legend isolated to the daring few who were driven to take on some of the greatest physical endurance challenges on the planet. With a growing fascination for major physical challenges during the nineteenth century, the end of the Victorian era witnessed probably the greatest ultra-endurance race of all time; Scott and Amundsen's ill-fated race to the South Pole. Ultra-endurance races continued through the twentieth century; however, these events were isolated to the elite few. In the twenty-first century, mass participation ultra-endurance races have grown in popularity. Endurance races once believed to be at the limit of human durability, i.e. marathon running, are now viewed as middle-distance races with the accolade of true endurance going to those willing to travel significantly further in a single effort or over multiple days. The recent series of papers in Extreme Physiology & Medicine highlights the burgeoning research data from mass participation ultra-endurance events. In support of a true 'mass participation' ethos Knetchtle et al. reported age-related changes in Triple and Deca Iron-ultra-triathlon with an upper age of 69 years! Unlike their shorter siblings, the ultra-endurance races appear to present larger gender differences in the region of 20% to 30% across distance and modality. It would appear that these gender differences remain for multi-day events including the 'Marathon des Sables'; however, this gap may be narrower in some events, particularly those that require less load bearing (i.e. swimming and cycling), as evidenced from the 'Ultraman Hawaii' and 'Swiss Cycling Marathon', and shorter (a term I used advisedly!) distances including the Ironman Triathlon where differences are similar to those of sprint and endurance distances i.e. c. 10%. The theme running through this series of papers is a continual rise in participation to the point where major events now require selection races to remain within reasonable limits. With the combination of distance and environment placing a significant physiological bordering on pathophysiological burden on the participants of such events, one question remains: Are we destined for another Scott vs. Amundsen? How long is too long?