Influence of Different Performance Levels on Pacing Strategy During the Women's World Championship Marathon Race.

Purpose
To analyse pacing strategies displayed by athletes achieving differing levels of performance during an elite level marathon race.
Methods
Competitors in the 2009 IAAF Women’s Marathon Championship were split into Groups 1, 2, 3, and 4 comprising the first, second, third, and fourth 25% of finishers respectively. Final, intermediate, and personal best (PB) times of finishers were converted to mean speeds, and relative speed (% of PB speed) was calculated for intermediate segments.
Results
Mean PB speed decreased from Group 1 to 4 and speed maintained in the race was 98.5 + 1.8%, 97.4 + 3.2%, 95.0 + 3.1% and 92.4 + 4.4% of PB speed for Groups 1-4 respectively. Group 1 was fastest in all segments and differences in speed between groups increased throughout the race. Group 1 ran at lower relative speeds than other groups for the first two 5 km segments, but higher relative speeds after 35km. Significant differences (P<0.01) in the percentage of PB speed maintained were observed between Groups 1 and 4, and 2 and 4 in all segments after 20 km, and Groups 3 and 4 from 20-25 km and 30-35 km.
Conclusions
Group 1 athletes achieved superior finishing times relative to their PB than athletes in other Groups who selected unsustainable initial speeds resulting in subsequent significant losses of speed. It is suggested that psychological factors specific to a major competitive event influenced decision making by athletes and poor decisions resulted in final performances inferior to those expected based on PB times.