The three main predictors of endurance performance are VO2 Max, energetic efficiency (or economy), and the lactate threshold.

noli's read

This advice is based on a solid consensus in exercise physiology. VO2 Max, or maximal oxygen consumption, is widely recognized as the physiological 'ceiling' determining aerobic potential (meta-analyses, e.g., Joyner & Coyle). The lactate threshold, which represents the maximum intensity sustainable without excessive accumulation of fatigue, is a robust marker for predicting long-distance performance (observational studies of athlete cohorts). Running or movement economy, which measures the energetic cost for a given speed, is also validated by research as a crucial differentiating factor between two athletes with a similar VO2 Max (randomized controlled trials). This claim is very faithful to current scientific literature. There is no exaggeration here, as Andy Galpin presents these elements as 'predictors' and not as sole causes, which is a scientifically prudent distinction.

the sources

1. 1Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W 2018