Runners often face a critical decision at the start of a marathon: how fast to go. Going too fast early can lead to depletion and collapse later, as seen in a marathon where a leader fell apart at mile 22. This highlights the importance of pacing as a risk management strategy.

Physiology plays a key role in pacing. Most runners slow down in the second half, with only a small percentage achieving a negative split. Starting too fast can deplete glycogen stores early, causing fatigue. Elite runners have adopted more controlled pacing, leading to better outcomes. Read more gear coverage.

Historically, marathon records favored fast starts and sharp declines. However, modern records show the benefits of even pacing. Elite runners like Paula Radcliffe and Eliud Kipchoge have set records by maintaining a steady pace, proving that controlled pacing leads to better results. Related: PUMA Launches FAST-RB NITRO Elite 2, Breaking World Athletics Rules.

This original Runner World brief is based on reporting from Athletics Weekly. Visit the source for its complete reporting, context and any later corrections.