A negative split means completing the second half of a race faster than the first. It is the pacing strategy used in the majority of world records across distance events — going out slightly conservatively preserves glycogen and delays fatigue, allowing a stronger finish. The opposite (positive split, where the first half is faster) is the most common amateur mistake. An even split (equal halves) is also valid. At marathon distance, a negative split reduces the risk of ‘hitting the wall’ late in the race.
Key points
- Second half faster than the first
- Strategy behind most world records
- Requires restraint in the early miles
- Reduces risk of bonking/the wall in marathon