The high-functioning, wealthy society of working age professionals. I think of the United States - and I assume most countries are the same, but perhaps to a lesser degree - as a cluster of societies that sometimes intermingle and share space with each other but are otherwise distinct. Obesity is a disease of the poor.
In certain circles there is a glorification of extreme forms of exercise. Partially as an indicator of status, to demonstrate that you have the both the personal agency and excess resources to pour into a training program to achieve impressive feats. But also as a sacrifice to the gods of success. All the respected leaders in business are doing ultra endurance sports, so it would stand to reason that there is something, some X-factor it's contributing to their ability to achieve.
It's worth asking whether there's any benefit to this kind of thing past a certain point. Are people their wasting time and causing long term damage to their bodies just to impress their friends?
Your last sentence, by the way, gave me a laugh. It could be the dictionary example for false dichotomy. Not sure whether this was intentional.