[pipodeclown]

I really don't see how this is not obvious. Evolutionarily speaking our survival strategy involved high amounts of exercise (running after antilopes and gathering plants/fruits) so our bodies are optimised for high amounts of exercise. At the same time we needed to survive in unpredictable and sometimes low calories invironnements, our behavioural instincts are therefore to gather and consume as much calories as we can while expending as little calories as possible in the process (binge eating while loafing around if possible). Such optimisations and instincts can lead to unwanted outcomes in new environments such as those of modern sedentary lifestyles.

I really don't see how you subjectively not feeling a benefit to an active lifestyle conflicts with the above.

[unsupp0rted]

It's not just me subjectively: our bodies are optimized for high amounts of exercise and yet when we give it to them they hate it and keep signaling for us to stop it.

"No pain, no gain"

Why would there be pain for doing what we're designed to do?

[atoav]

Because most people weren't doing hunting or labor because they liked it[1]. They just liked dying even less. People of generations before modern times led often extremely short and miserable lifes. Not moving meant dying. Moving more than was necessary also meant dying.

We werent designed to do sports, it is just that those who didn't move were a little more likely to die. And people who are more likely to die are less likely to pass their genes on, simply because they had less time to reproduce. The result: We have bodies which are meant to be moved, but only if needed, like many other animals. Moving too much was bad too, as resources are needed to do it an resources were not readily available at all times [cue picture of rough European winter ca 1300 AD]. You probably guessed already that starvation, because you burned too many calories has luckily become a non-issue in most parts of the world.

So we are a direct result of the environments and circumstances our ancestors lived in, managed to get kids in, and who in turn managed to survive long enough to raise their kids.

[1] Many people actually like moving or grow to like it. A bit like with spicy food, which hurts at first, but pours out endorphines, being fit and using your body can give you all kinds of good emotions during and after the activity and you can grow to like it once the pain is over. Being able to rely on your body and know it and its limitations can be very fulfilling. When I run my Sunday 16km I don't feel any pain. But I am fit. I might feel pain when I attempt a marathon and try to set a personal record. But regular running is a breeze once you are in shape.

[edanm]

What about childbirth? Do you think that we weren't designed to have children?

I think you're mixing up a few things here. The reason things hurt is because you are doing physically demanding things with your body. Evolution can't just make something which takes a lot of energy not take that energy. It could get rid of the idea of pain entirely, but that's bad for a lot of other reasons.

That's like asking why our bodies were even designed to get food in the first place instead of not needing it. There are physical constraints involved.

[pandaman]

Pain-gain thing is specific to the methods of training. People intentionally cause muscle damage to initiate hypertrophy and quick muscle mass gain. Humans naturally grow a lot of muscle tissue when they grow up without doing damage/repair hack and without pain. There are also other methods of training, say "zone 2" for endurance and power, that is virtually painless.

[7e]

It’s because food used to be scarce. The body experiences pain as signal to conserve food/energy, which improves survival.