This article for me seemed to miss the obvious point of endurance sport as status display. This also highlights the limit of the research methodology, because very few people will acknowledge that they participate in these events to display evolutionary fitness, or are even aware of this compulsion. So what you may have in these results is some confounding of drivers: people more inclined to display status want both to earn more money, and look fitter to display evolutionary status. The phenomenon described in the article could be correlation not causation, and I’m a little surprised this was not investigated.