Long-distance running only the placing is of importance. Other less popular variants such as fell running, trail running, mountain running and tower running combine the challenge of distance with a significant incline or change of elevation as part of the course. Multisport races frequently include endurance running. Triathlon, as defined by the International Triathlon Union, may feature running sections ranging from five kilometres (3.1 mi) to the marathon distance (42.195 kilometres, or 26 miles and 385 yards), depending on the race type. The related sport of duathlon is a combination of cycling and distance running. Previous versions of the modern pentathlon incorporated
Spirit of the Marathon Salazar, Grete Waitz, Paula Radcliffe, Joan Benoit-Samuelson, and Kathrine Switzer provide commentary about the sport. The focus is then on the six featured runners and their training for the 2005 Chicago Marathon. American Deena Kastor and Kenyan Daniel Njenga are both elite runners, and are determined to win the race. Kastor was the bronze medalist at the 2004 Olympic Marathon, but has yet to win a marathon. Njenga had finished second multiple times in previous Chicago Marathons. Kastor is shown training and recovering from an injury in Mammoth Lakes, California, while Njenga's life as a sponsored runner in Tokyo is