How much should a person exercise daily to stay healthy?
I got a new view on this by reading an article by Wim Kohler, it has the title 'A person is made to move'. He discusses a book written by Harvard professor Daniel Lieberman.
Professor Lieberman was looking for answers to the question why we don't find training as fun and enjoyable as socializing, food and sex? Why do we invent reasons for delaying and canceling it, even though we know very well that it is healthy?
He looked for the answer in human evolution and did a lot of research among the increasingly scarce specie of the so-called 'hunter-gatherers' in this world.
Millions of years of evolution have produced a human body that is adapted to walking on two legs and can throw, carry and do a lot with the hands.
The new insight is that body repair and maintenance (or also 'rejuvenation') in that walking-oriented body almost only takes place during or after exercise. Anyone who does nothing will decay and age. When muscles contract, it causes an avalanche of messenger molecules. Initially, they immediately release energy, but eventually molecular processes are initiated for maintenance and repair. Exercise could prevent diseases of affluence. Lieberman does not call it diseases of affluence, but mismatch diseases. They arise because we no longer allow our body the movement for which it was made.
Lieberman also believes that humans did not evolve to train. Hunter-gatherers never train. Training is exercise for fitness and health, without directly producing food or children. It takes energy. For the hunter-gatherers, food was not readily available and each calorie can only be spent once. Growth, body maintenance, foraging for food, stockpiling or reproduction, that's what it was all about. Sitting was -and is- a favorite activity of hunter-gatherers.
But Lieberman saw during his observations that hunter-gatherers are much more active when sitting. They are busy with the children or preparing food, they sit on the floor, often shift their positions and stand up for a while. And in addition, those hunter-gatherers move purposefully for 5 to 10 hours a day. Nowhere in his book does he recommend extending the exercise guidelines from 5 hours a week to 5 hours a day. But our body is made for it.
Lieberman also knows that hunter-gatherers don't have big muscles at all and are not that strong. They don't need that and a muscular body requires a lot of energy for maintenance.
Movement, such as contracting muscles, does not have to be running or with force. I find that being busy, walking and sitting actively is a beautiful and calming perspective.
Even in old age, our body needs exercise for maintenance and repair of, among other things: organs, muscles, nervous system, bones and cartilage. The aging is due to all those different substances that are released en masse during exercise and are nowadays much researched. Not moving when aging is, in Lieberman's words, an evolutionary mismatch that accelerates aging.
Ultimately, Lieberman favors nudge; give it a push in the desired direction. Provide information, have doctors prescribe exercises more often. He also promotes self-organization: make appointments with roommates and friends, play sports together, create variety, find a nice environment, do it often, choose a realistic goal - not based on performance, but on eventful time, and reward yourself.
In this newsletter I therefore call on everyone to lead an active life with a lot of muscle contraction.
The book is titled ´Exercised – The Science of Physical Activity, Rest and Health´.
