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4 myths about how the human body works by Daniel Lieberman's book "The Exercise Paradox. A Scientific Look at Physical Activity, Recreation, and Health"

Hi!

We recently read a popular science book by evolutionary biologist Daniel Lieberman called The Exercise Paradox.

Collected for you myths, theses, and new scientific research.

 

In this article, we will debunk the myths that:

 

  • We were made for exercise.
  • Laziness is unnatural.
  • Sitting is not healthy.
  • Eight hours of sleep is the norm.

Myth 1: "Evolution shaped us with exercise in mind."

Advertising campaigns, propaganda and years have molded us into thinking that modern man is overcome by laziness and we are getting further and further away from evolution's "design" of being athletic.

 

The ideal man according to this myth is an athletic savage.

In 1945, UN scientists studied the physical activity level - PAL (physical active level) - of people from different occupations and parts of the world. The level is measured "as the ratio of the amount of energy you expend in a day to the amount of energy your body would need to maintain its strength if you were in bed 24 hours a day.

 

In office workers without additional activity PAL is equal to - 1.4-1.6.

With extra activity per hour, it's 1.7-2.0.

Hunter-gatherers have 1.8-1.9, i.e., only 15% higher than office workers in the same states.

CONCLUSION: The difference in physical activity among these groups of people is not so great as to berate themselves for a sedentary lifestyle.

Myth 2: "Idleness and laziness are unnatural to man"

There are two theses here:

  1. The human body consumes energy even at zero activity. An average man weighing 80 kg consumes about 1700 kcal in a state of complete rest. The body uses energy for breathing, digestion, thought processes, etc.
  2. The body allocates energy in five ways in descending order of priority: reproduction, physical activity, storage, body repair, and growth.

That is, evolution is moving us toward inactivity so that we stay at rest as long as possible and don't spend a lot of energy on functions on the post-reproduction list.

Conclusion: even when we are not doing anything, we are actually doing it. And when we scold ourselves that we need to be more active, our body reminds us that it is better to save energy for important things.

Myth 3: "Sitting is as harmful as smoking"

Several scientists have calculatedthat predominantly sedentary physical inactivity equates to the harm of 3 cigarettes a day.

 

Lieberman expressed doubts about these scientists' hypotheses on this point and cited some studies.

 

For example, here's the mathThe difference in energy expenditure between standing and sitting is only 8-10%. A person weighing 80 kg is 8 kcal/hr.

 

We don't sit as much as it seemed. The average American spends 50-55% of time in a sitting position, while chimpanzees spend 87%.

 

But the main arguments against sitting still are as follows:

 

  1. While you're sitting down, you could do some physical activity.
  2. Prolonged inactivity raises blood glucose and fat fractions.
  3. Sitting encourages our immune system to attack our body.

 

Each of them has a scientific basis, and yes, there are dangers. What does the author say?

 

A) Learn to sit actively. Those who have incorporated active five-minute stretches into a sedentary lifestyle have up to 25% less internal inflammation.

B) Twirl, fidget, fidget. You can spend 20 kcal/hour more this way.

B) Slouching is part of the evolutionary process, and good posture is a sign of a trained back and does not save us from pain.

Conclusion: It is not sitting that is harmful, but inactivity. Change your postures, have active moments and you will be healthy.

Myth 4: "You need to get eight hours of sleep every night."

A little rundown: one of the key sleep functions - to sort through impressions, make sense of them, and discard what is unnecessary. Another function is to remove energy waste in the form of cellular debris. This is accomplished by the brain's "plumbing" system and cerebrospinal fluid.

 

How much sleep do we get in reality?

 

Adults in the United States, Germany, Italy and Austria sleep 6.5 hours in summer and 7-7.5 hours in winter. And the Hadza tribe, who have no electricity, gadgets, watches and internet access, sleep for 5.5 - 6.5 hours. 

 

And several other studies suggest that people with 8 to 12 hours of sleep have a 13% increased risk of mortality.

 

What about the quality of sleep? Are we sleeping better?

Anthropologist Carol Wortman suggested the opposite: that the quality and quantity of sleep compared to the sleep of our ancestors is negatively affected by certain rules of sleep hygiene: silence, separate blankets with a partner, etc.

Conclusion: i.e., being more attentive to sleep made sleep shallower and longer.

The book in its entirety can be purchased at Labyrinth Or at other online retailers.

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Submit a request for a free first session with a guidance counselor to get to know each other, determine your goals, and match your child with an educator
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Submit a request for a free first session with a guidance counselor to get to know each other, determine your goals, and match your child with an educator
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Submit a request for a free first session with a guidance counselor to get to know each other, determine your goals, and match your child with an educator
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Submit a request for a free first session with a guidance counselor to get to know each other, determine your goals, and match your child with an educator
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Submit a request for a free first session with a guidance counselor to get to know each other, determine your goals, and match your child with an educator