Road-race distances, in kilometers. 5K is 3.1 miles; 10K is 6.2 miles. The 5K is the shortest common road-race distance and is a good choice for a beginner who wants to experiment with racing. When these distances are run on a track, they are typically referred to as "5000 meters" and "10,000 meters"; "5K" and "10K" refer to road events.
Running out of fuel during exercise. See "Hitting the Wall."
An easy, slow run after a hard workout or race, used to flush lactic acid from muscles and speed recovery. (See also "Warm-up.")
Using one sport's training methods to train for another sport. Cross-training is often implemented to add variety, to allow an athlete to maintain fitness while injured, or to increase training volume without creating imbalances through overuse. For a runner, cross-training often includes alternative aerobic activities like cycling, swimming, and gym ergometers (elliptical trainers, spin-class cycles, etc.) and/or strength/flexibility exercises such as yoga, Pilates, and weight training.
Swedish for "speed play." Fartlek workouts involve running at various paces, sometimes for random or unpredictable amounts of time, in order to build speed and endurance and to prepare for unexpected pace-changes in races.
Gun time is measured from the official start of a race until a participant crosses the finish line. Net time is the time between when a runner crosses the start and finish lines, as recorded by a D-Tag, B-Tag, ChampionChip, or other device. In NYRR events, finishing place is determined by net time; gun time has no bearing on place, except for that of the race winner, who must be the first runner to cross the finish line.