How Running works

Track running splits into sprints, middle distance and distance, and each demands a different physiology. Road racing adds the marathon and half marathon, and cross-country adds terrain and weather as variables.

• Sprints — 100 m, 200 m, 400 m, run entirely in lanes
• Middle distance — 800 m and 1500 m, tactical and often slow early
• Distance — 5000 m, 10,000 m, run in a pack
• Road — half marathon and the 42.195 km marathon
• Hurdles, steeplechase and relays add obstacles or handovers

Races up to 400 m start from blocks in a crouch; longer races use a standing start. Reaction time is measured electronically, and anything under 0.1 seconds is ruled a false start on the basis that no human can react faster than that. A single false start means disqualification.

• Reaction under 0.100 s is automatically a false start
• One false start disqualifies the athlete
• Sprints up to 400 m are run from starting blocks
• Lanes are staggered so every athlete runs the same distance

Sprinters stay in their lane for the whole race; straying out of it is a disqualification. In the 800 m athletes break for the inside after the first bend, and in longer races they run in a pack from the gun. Cutting in front of another runner and causing them to break stride is obstruction.

A sprint or jump record only counts if the following wind is 2.0 m/s or less, which is why some very fast times never enter the books. Road records require a course that is properly measured, does not drop more than a metre per kilometre, and does not finish too far from where it started — rules that exist to prevent downhill, wind-assisted courses.

• Maximum legal tailwind of 2.0 m/s for sprints
• Course measurement and elevation limits for road records
• Times must be recorded by fully automatic timing
• Athletes must pass anti-doping controls for ratification

Four runners pass a baton within a 30 m changeover zone. Drop the baton or pass outside the zone and the team is disqualified regardless of speed. Because the outgoing runner is already accelerating, a well-drilled relay team runs substantially faster than the sum of its individual times — and the fastest four runners rarely make the best quartet.

Carbon-plated shoes with thick foam midsoles arrived in 2016 and improved running economy by a few percent — enough to rewrite the distance record books within five years. World Athletics responded with limits on stack height and on the number of plates, rather than banning the technology outright.