Asking the same question whether it is more important to be physically or mentally tough not when climbing Mount Everest but to run a mountain ultramarathon there are no studies to refer to. There are however plenty of studies of mental coping strategies during running in general. A good recent review is “Do 'mind over muscle' strategies work? Examining the effects of attentional association and dissociation on exertional, affective and physiological responses to exercise” by Lind and colleagues published in Sports Med 2009; 39: 743-764. As the title says, the article focuses on different dissociative (for instance listening to music while running) or associative (for instance focusing on the breathing or heartbeats while running) strategies. I will write more about this in a later blog post, but the current research tend to favor association as a better coping strategy to avoid to “hit the wall” during long endurance events, at least when racing, and this is also my personal strategy for the most part, even though I put on some music for instance some of the nights during TDG. A very interesting recent article I read was about the positive effects of “self-talk” on endurance performance by Blanchfield and colleagues in pre-print in Med & Sci in Sports & Exercise.
It is clear that we use mental strategies to control the physical strain and there are indications that this is more important during longer running than shorter (see for instance “How do humans control physiological strain during strenuous endurance exercise?” by Esteve-Lanao and colleagues in PLoS ONE 2008; 3: e2943). There is also a lively debate about the so called central governor model of regulation of fatigue proposed by primarly Timothy D Noakes (see for instance “The central governor model of exercise regulation applied to the Marathon” in Sports Med 2007; 37: 374-377). My personal view is that, albeit physical preparedness is essential to complete a mountain ultramarathon, mental toughness is more important both while training before and during the actual race.