Mariner has not had much physical exercise for the last two weeks because he had a houseful of guests. Today he decided he better start walking to the Post Office again because he felt aches and pains all over, that is, stiffness, muscle complaints and loss of gumption.

So he walked to the Post Office – a  brisk 10 minute walk each way. While walking he felt no unusual discomfort; true, he wouldn’t make the Olympic team but generally, it was a pleasant experience – until he arrived back at the house. Exhaustion set in and general malaise. The next hour or so he simply sat in his chair.

He is reminded of a post he wrote some time ago that suggested walking or running was good for a human. This is because when walking or running, the brainstem takes over bodily functions in such a way that the functions of the body (blood pressure, breathing, circulation, etc.) focus on sustaining the needs of walking or running. Only afterward are deficiencies dealt with.

Anthropologists have identified this deference to walking and running as a survival trait during the days in the Rift Valley and the Serengeti in Africa. In those times, we didn’t have houses, cars, roads, chairs, grocery stores or telephones. Survival meant chasing down food that often ran faster than humans.

What transpired in evolution was that the brain adapted a way to sustain walking and running – sort of putting the body in overdrive. This included perspiration and adapting various body functions so that sustained running and walking received maximum support.

What is fascinating is that the brainstem, one of oldest parts of the brain, still retains an on-off switch that switches on only when we walk or run. When the switch is on, the entire chemistry of the body gets a workout.

Mariner is sorry that the early humans didn’t have a chair to flop into when it was over.

Ancient Mariner