People who can run every day are much healthier than people who can't run every day. People who continue to be able to run every day beyond middle age are exceptionally healthy compared to their peers. It's really hard to disentangle the cause from the effect.

Between that and running injuries, car/bike accidents, skin cancer, etc, it probably wouldn't be tooo hard to show that running is not worth it.

Mind you, I'm NOT MAKING THAT ARGUMENT, I'm just saying it's probably easier to do than you imagine.

Um, there actually are peer-reviewed studies which address things like running and health. For example, "The Influence of Running on Lower Limb Cartilage: A Systematic Review and Meta‐analysis," Sports Medicine (2022) 52:55–74 [1]

One conclusion is "Results suggest that cartilage recovers well from a single running bout and adapts to repeated exposure. Given that moderate evidence indicates that running does not lead to new lesions, future trials should focus on clinical populations, such as those with osteoarthritis."

My understanding is the evidence for walking is much stronger than running given the assumption that an "active lifestyle" is a goal, rather than just living longer.

[1]: https://doi.org/10.1007/s40279-021-01533-7

> It's really hard to disentangle the cause from the effect.

I have to laugh. No it’s not. It’s not like healthy people just from the fact that they are healthy have some odd quirk of occasionally randomly tripping into a 30min run without any say in the matter.

Regular running causes an improvement in health.

Improved health does not cause regular running.

I'm a life scientist: it's true that physical exercise has a causal effect on positive health outcomes. However, if you believe demonstrating cause is simple, you don't know enough about science or statistics. It's extremely difficult.

My comment was purely rhetorical, and that was partly my point. The other part of my point is that no matter how carefully you try to account for the costs and benefits of some activity, there are intangibles and benefits that are extremely difficult to convert into dollars (much like the value of a human life when expressed in dollars).

(My comment was not an attempt to refute or disprove the main thesis, but I do think it's important to step back and ask: "what's the point of education? is the point just to make a profit?")

I honestly think spreadsheet makers could argue both sides without problems.