400m Rules

The 400m is the event novice athletes misjudge most often, going out at near-sprint pace and slowing dramatically over the final hundred metres. The standard model is to run the first 200m about a second slower than a flat-out 200m and hold form thereafter.

Nobody actually accelerates in the last 100m of a 400m; the winner is whoever decelerates least. Framing it that way to newer athletes changes how they run the third bend, which is where the race is usually decided.

The 400m is run entirely in lanes with a large stagger, and athletes must stay in their lane for the whole lap. Stepping inside the line on the bend is a disqualification, which catches tired athletes on the final turn.

Because of the full stagger, athletes cannot judge their position from the field until the final straight. Seeded lane allocation matters here too, with middle lanes generally regarded as the fairest draw.