Triathlons typically consist of swimming, biking, and running in direct succession. Events can range from youth to ultra distances and include 50 to over 3,000 competitors. The first modern triathlon was the Hawaiian Ironman Triathlon which included a 2.4 mile swim, 112 mile bike, and 26.2 mile run. Key regulations include separating races into amateur and professional categories divided by sex and age where athletes cannot receive outside assistance.