  Objectives: Negative splitting (i.e., finishing the race faster) is a tactic
commonly employed by elite marathon athletes, even though research supporting
the strategy is scarce. The presence of pacers allows the main runner to run
behind a formation, preserving energy. Our aim is to show that, in the presence
of pacers, the most efficient pacing strategy is positive splitting. Methods:
We evaluated the performance of an elite marathon runner from an energetic
standpoint, including drag values obtained through Computational Fluid Dynamics
(CFD). In varying simulations for different pacing strategies, the energy for
both the main runner and his pacer were conserved and the total race time was
calculated. Results: In order to achieve minimum race time, the main runner
must start the race faster and run behind the pacers, and when the pacers drop
out, finish the race slower. Optimal race times are obtained when the protected
phase is run 2.4 to 2.6% faster than the unprotected phase. Conclusion: Our
results provide strong evidence that positive splitting is indeed the best
pacing strategy when at least one pacer is present, causing significant time
savings in official marathon events.
