I would submit that, prior to making it a part of our vernacular, exercise might have been considered unnatural in every day life in the U.S. Improvements to the body were primarily a product--not a goal--of outdoor physical activity and physical labor. Prior to the last 3-4 generations, due to time constraints and family obligations, long hours of physical work in place of gym memberships was the standard. Even athletes didn't have annual contracts, and had to return home in the off-season, to work. Professors, once the 9-month contract was completed, had to find summer work off-campus until fall classes. Over time, due to a plethora of factors, and depending on an individual's socioeconomic status/affluence, exercise has replaced physical labor in some populations. Fortunately, we still have a large segment of the population that still performs physical labor to keep things running. Without them, meeting our basic needs for warmth, food, water, and shelter would be hit or miss. And who would build and maintain the treadmills and exercise bikes? Over time, the pendulum always swings back--how much always remains to be seen--but the challenges of the pandemic have certainly caused many to reassess the traditional exercise paradigm.

Michael Meyers, thanks for the contribution. Exercise is essentially work, and work usually requires discipline, motivation and goal. Most people are being told to do exercise either to achieve better health or better looks. There's no biological urge to do exercise that comes from within the body itself. Hunger is an example of how the body produces and sends signal to eat to maintain life. I'm not aware of any chemical or hormone that makes the body want to do work or exercise. It seems that exercise is not essential to be alive or to maintain life. Do wild animals exercise? Does the cheetah run around at 60 miles an hour just for exercise? What about the gorilla? Does do gorilla do weight training exercise to be strong? Humans seem to be the only animal who have evolved to such a state that many basic functions required to maintain life in the distant past are no longer needed for survival.

As for the hormone thing, dopamine is related. Maybe you can search more about it.

Thank you, Xiaoou Cheng, for your reply. Yes, dopamine, serotonin, and norepinephrine are among the neurotransmitters being influenced by exercise. Exercise stimulates the production and secretion of neurotransmitters and hormones. Too much exercise may produce hormone imbalance. There's no neurotransmitter or hormone, however, that makes people exercise. Exercise is a learned behavior and activity as byproduct of modern living.

Our need for exercise used to be met by the way our social systems were organized, but as modern societies have evolved to only value the achievements of high performance athletes, exercise has become much less a part of 'natural' activity.

Thank you Franklin Lue.

I'm not sure if there's an urge or need that the body feels to cause to exercise the way we do now. Sports are created simply for entertainment/amusement and pastime and not at all for the purpose to exercise the body. When humans used to hunt and gather for the food to maintain life, they used their bones and muscles to run after the preys and to gather the food wherever they could find. That means they used their strong legs to walk and run for miles, and they used their arms and hands to pick and carry food stuff. What do we do now? How many jobs do we have now to sustain life that require strong legs and arms? How do we acquire food now? Humans don't even need to use their legs much anymore because they can easily get what they want made and delivered for them. Modern transportation virtually eliminates human dependency to use the legs as mode of mobility and transportation. The same goes with the hands and arms, how much strength does it take to use a pen or keyboard? There are still some manual labor works out there, but by most accounts, those works are done by very few people and will eventually be eliminated by machines. The long limbs and the organs the body possesses have evolved the way they have because of use and necessity to maintain life. What's not being used and not necessary will eventually atrophy and be of no use or even disappear altogether.

Ben, your original question on exercise being "Natural", possibly presupposes "Natural" is a unitary concept. Your line of discussion above, emphasizes the relative nature of exercise and function, including social. From what i recall of the studies that have been conducted on humans in 'isolation' conditions (i.e. without any light & very limited social contacts), they tend to maintain a pattern of activity that approximate walking a few kilometers 'daily'. I hoped this helps to clarify my reply to the original question.

Franklin, thank you for the clarification. But, I don't think we're talking about the same thing. I'm not very good at semantics and don't intend to discuss the philosophical meaning of words. By "exercise", I mean physical activity that will maintain physical fitness or will make it better. By "natural", I mean "inborn" or things we're born with such as eating when we're hungry, etc. There are many reasons why people exercise including health and enjoyment, but all of those reasons are learned behaviors and not inborn. Doing basic daily chores is not the same as exercise performed to maintain health or for amusement. The ancestors never had to "exercise" because most of their activities to fetch for food and to stay alive required rigorous physical activities.

If you read the studies conducted on humans in 'isolation' conditions (i.e. without any light & very limited social contacts), you will see that the authors often make the case that the physical activity pattern of a few kilometers 'daily' is a part of regular behaviour. This activity is most often not a part of their daily or required chores. In fact in at least one of the papers, i recall the authors are amazed at the activity for its' regularity, despite the lack of environmental cues or feedback for its' distance.

I wonder if we ever take time to think and wonder why we have long limbs. What are the long limbs for? What purpose can they possibly have in our daily life for us to survive? I see the lions with their strength, the cheetah with their speed and the monkeys with their long arms, they all possess those physical traits so they can survive. They actually use those limbs and muscles to survive. Are our arms made so we can lift the dumb bells in the gym and to do bench presses so that we can survive? Are the long legs made so can run on treadmill?

Ben:

You might have seen news report a few weeks ago of a group of more than 10 volunteers emerging from a cave in France after about 40 days in isolation. They are part of a Deep Time project (https://deeptime.fr/en/) and were all wearing activity monitors, so should be able to extend the available data on activity & ' daily behaviour'. This group is larger than any of the previous studies i recall, so will probably contribute of the effect of socialization; although the time period is much to short to begin to address the evolutionary issues you raise with 'selective advantages'.

You're right. Thanks Franklin. Isolation produces sensory deprivation. I'm somewhat familiar to the effects of sensory deprivation on both the physical and psychological aspects of such experience. The only thing is the fact that most people do not experience sensory deprivation. It's actually the opposite. Modern humans experience sensory overload which could explain some of the unnatural activities humans seek to balance their life. Thank you for your insight, Franklin.

If the body weight and waistline are within the ideal numbers, if the blood pressure and blood sugar are within the normal limits for healthy individuals, if the body and mind do not suffer from overconsumption and sensory overload, and if father time is kind enough to let us age gracefully and beautifully, is there a reason to exercise?

Personally i sleep better when i exercise regularly; it help to maintain the balance in living you outline above.

This provocative question is meant to give some insight to our evolutionary state of being, and I was hoping to have a good discussion regarding the topic. Exercise, is without a doubt, good for health and necessary for modern living to achieve a good quality of life. Exercise and other forms of stimulation are necessary to maintain good condition and function of many organs that rely on repetitive stimulation to function and to function well. When an organ is not being stimulated and exposed to the required input to function, it will eventually atrophy to a point of non-existence in term of its functionality. Take eyesight for example. After birth, if the eyes are kept shut and there's no exposure to light and images to stimulate the neurons in the brain, the eyes will not see because the organ will not develop due to the lack of necessary stimulation as can be seen in some creatures of the deep sea where a total and complete darkness is the norm. How smart will the brain be if it's not exposed to learning and knowledge? Musculoskeletal system is no difference, it requires stimulation in a form of physical activities which is now called "exercise" to maintain its strength and function. The interdependence of the body's organ system also has proven that certain physical and mental exercises have a wide range of positive effects on the other organs as well such as the cardiovascular system and the brain complex system both with its neuroendocrine and neuropsychological aspects. The cardiovascular system consists of the heart which is basically a living pump made up of muscle fibers wired with automated network of electrical impulses for the pump to run and being connected to blood vessels acting like conduits to transport blood. The system needs to be stimulated and maintained to be able to meet the many different demands that life requires. Since the lifestyle choice of modern living carries significant risks to the cardiovascular system, exercise has become a part of healthy regimen to combat the issue. It's the same with the neuropsychological and neuroendocrine aspects of the brain. Exercise will stimulate and produce a cascade of stimulation that is beneficial for the overall health. Sleeping well at night is one of the beneficial and positive effect of exercise as mentioned by Franklin. Exercise is work but it's well worth it and a significant part of a healthy life.

Ben, as you so eloquently state above ....living things have a great capacity to adapt.....perhaps that whats they are living and eventually can develop the capacity for self awareness.

As the holiday season comes into full gear and the year comes to an end, many people may be thinking about starting regular physical exercise as a new activity for the new year whether to keep fit or maintain ideal body weight. Throughout the years, there have been so many commercially well-known products from gym membership to home gadgets that people can do at home. Whether the gyms are used for exercises or for socializing, the lure to get new members to replace the members that quit is pretty much constant. Why do people quit the gym? As for home gadgets are concerned, they lure people with all kinds of gimmicks. They even make gadgets that require no actual conscious muscle contractions. The gadgets have electrodes to actually stimulate and contract the muscle fibers for you. People can buy a very expensive stationary bicycle and have a coach appear on a monitor screen cheering you on while exercising. Whether it's the gym or home gadgets to do exercises, most have failed and do not have much staying power. People eventually quit the gym for whatever reason, and the gadgets end up collecting dust or parts of a garage sale. Physical exercise to keep fit and to spend the extra calories consumed requires both work and commitment. One form of natural activity that people forget and underestimate that can still be used as an exercise to keep fit and healthy is "walking". The long lower limbs are perfectly made and have evolved to be used so we can be mobile and independent to move from one place to another and not only from the couch to a dining chair or inside the house to a driver's seat of a car.