Modeling: Optimal marathon performance on the basis of physiological factors

This paper examines current concepts concerning 'limiting' factors in human endurance performance by modeling marathon running times on the basis of various combinations of previously reported values of maximal O₂ uptake (V̇.O(2max)), lactate threshold, and running economy in elite distance runners. The current concept is that V̇O(2max) sets the upper limit for aerobic metabolism while the blood lactate threshold is related to the fraction of V̇O(2max) that can be sustained in competitive events greater than ~ 3,000 m. Running economy then appears to interact with V̇O(2max) and blood lactate threshold to determine the actual running speed at lactate threshold, which is generally a speed similar to (or slightly slower than) that sustained by individual runners in the marathon. A variety of combinations of these variables from elite runners results in estimated running times that are significantly faster than the current world record (2:06:50). The fastest time for the marathon predicted by this model is 1:57:58 in a hypothetical subject with a V̇O(2max) of 84 ml · kg^-1 · min^-1, a lactate threshold of 85% of V̇O(2max), and exceptional running economy. This analysis suggests that substantial improvements in marathon performance are 'physiologically' possible or that current concepts regarding limiting factors in endurance running need additional refinement and empirical testing.