alt Hacker NewsWhich is way more than what original hunters and gatherers ever clock. They do move a lot, but not so much, and they alternate their activities a lot too (running, walking, resting, taking entire days off and just guarding their village).
We're not really optimized for this sort of extreme endurance and long-term development of serious pathologies is unsuprising.
You shouldn't so offhandedly assume a hunter-gatherer lifestyle couldn't lead to issues like increased risk of CRC, or that activities which lead to increased risk of CRC couldn't be what hunter-gatherers did. Evolution is neither fast nor perfectly precise. Plenty of animal populations have common health problems that simply weren't harmful enough to reproduction to be selected out, much less something rare and late-onset like CRC.