People run for many reasons.
One of the reasons that many would cite is "for the experience".
In the ultramarathon running populace, the proportion of people who run "for the experience" is higher than in the general running population (from what I have observed).
This is in large part because the experience of running is hugely intensified (in a good or bad way) by the extreme fatigue inherent in the events that we participate in. This fatigue-induced experience is what draws many people to keep increasing the distances that they cover on foot past the reasonable length for good health and eventually to beyond the marathon mark.
This "for the experience" attitude is characteristic of the ideological stage of consumption-driven capitalism in which we find ourselves in the 21st century. Slavoj Zizek broadly describes the three stages in this video (from about 30 minutes on).
Previously (i.e. at the beginning of last century), when buying an object, we were sold (i.e. marketed) its inherent qualities. Later on in the history of bourgeois society, we were sold its ability to elevate our social status.
Now, we are being sold an experience; we are being sold the satisfaction of our softer emotions, of our loftier need to feel and to be in the world.
Zizek's much(over?)-used example of this is the cup of Starbuck's Coffee; we are told that by purchasing a coffee we will help to save "starving children in Guatemala". In fact, by buying that cup of coffee, we are helping to reproduce the system that causes the starvation (by feeding money to the huge corporation), while doing an infinitesimally small amount to alleviate it.
What is important about buying that cup of coffee for us is that it satisfies our internal need to think beyond ourselves, to empathise with others, to understand ourselves as virtuous (charitable) human beings and, on some level, to humanise the inhuman system in which we live.
Running an ultramarathon is by no means the same as chugging down a soy cap from Starbucks, but the result of running ultras is similar. Many of us pursue this passion to satisfy the need to subjectively position ourselves in the world; for example, to understand ourselves as virtuous (unlike the apparently lazy masses) human beings or to "free" ourselves from the system, if only for a few hours.
Many people would cite the critical difference between these two actions, as far as their "authenticity" is concerned, as follows:
Purchasing a coffee to be drunk is an act of commodity consumption, whereas running an ultramarathon is not. Therefore, the feelings of satisfaction and freedom that people achieve from the latter are somehow more "real" than those generated by the former - that somehow, by running an ultra, we are actually freed from the capitalist logic for the duration of the run.
This is a very decontextualised understanding of ultrarunning.
In the process of preparing to run an ultra, we purchase countless commodities - shoes, back packs, t-shirts, shorts, gels, energy bars, etc, etc, etc... so that on the day, we can undergo a "truly authentic" experience.
This consumption, we are told, is secondary to the experience. But this consumption is also essential, in order to get to the point where we can have the experience.
So, with this in mind, I would argue that ultrarunning represents a different, more seductive ideology in consumption-driven capitalism.
People who claim to see behind the veil of directly consuming experience prefer to directly experience, with consumption being facilitative of this experience.
With the advent of major ultrarunning brands and news websites, the idea that consumption (of shoes, back packs, etc) is essential to facilitating the experience is gaining more and more strength in the minds of the sport's participants. It is being solidified as ideology.
It is in this way that ultrarunning does not free us from the system. It represents a capitalist logic for people who wish to escape capitalist logic.
It gives us the illusion of freedom while drawing us into consumption in a more subtle and subversive way.
So my point is really that we can't escape this logic by consuming something more ethical, or consuming for the purpose of doing something authentic.
Authenticity and freedom in ultrarunning is an ideological illusion.
There is really no way out (on a personal level: leaving out other, more revolutionary solutions) as consumption, on some minimum level, is necessary.
With that said, a partial exit could be made by simply consuming less.
Similar ideas are explored in Ultrarunning and Capitalist Ideology 2.