Predictably Unpredictable

What factors predict performance in ultra-marathons? If we know the answer(s) to this question, and keep Goodhart’s law in mind, we can make better decisions about where to emphasize training time.

In a new paper titled, Physiological Determinants of Ultramarathon Trail-Running Performance, the authors examined predictors of performance in athletes who completed either a 50-, 80-, or 160-km trail race over a 20-km loop course on the same day.

Here are the key findings statements

While classic determinants of running performance, including cardiovascular health and running fitness, predict 50-km trail-running success, performance in longer-distance races appears to be less influenced by such physiological parameters.

and

In the 80-km race, only peak velocity achieved in the maximal oxygen uptake test predicted performance. In the 160-km race, there were no significant performance determinants.

If you’re training for shorter ultras (or sub-ultra events), then greater fitness can really help your performance. If you are training for longer events, like 80-100K, then you should continue to emphasize overall speed (making faster paces feel easier), and place greater attention on other factors. These other factors are what I call ‘self-maintenance’ and include eating, hydrating, smoother downhills to minimize leg damage, foot-care, mindset and self-talk, etc. If you’re preparing for 100-milers or longer, then you likely have the fitness and speed required. Don’t stop training those but do place a lot of emphasis on developing the additional skills of self-maintenance.