Our body is made to work hard. In contrast to most machines that abrade with their use, the human body functions the opposite way. The body supports structures that are in use and regards those not used as superfluous and catabolises them. We are always in the making and the metabolism will not maintain unnecessary tissues. The most obvious example are the muscles. Being in bed, e.g., due to an illness, leads to a considerable reduction of muscle mass within a few weeks. Only with their continuous use, our muscles remain strong. The same happens with the bones.


Osteoporosis is a good example how movement and exercise are important. Osteoporosis is a disease of elders characterized by bone loss and a disturbed microarchitecture of the bone. The disease is not a problem by itself. The problem is that osteoporotic people easily suffer fractures if they fall. Osteoporotic fractures are a major reason for untimely death and prolonged suffering. Therefore, it is equally important to maintain bone stability and to avoid falling. Exercise is the best prevention for both. Firstly, it reduces the natural loss of the bone mass. Secondly, even if the (measured) bone mass is reduced, exercise improves the quality of the bone, its microarchitecture. Thus, the bones remain stable. Thirdly, exercise improves balance and mobility. People are less prone to fall and if they do, they do it more smoothly.

Younger people are not concerned with osteoporosis. Towards the end of their twenties their bones have reached the so-called peak bone mass. The bone is not only very stable, a high peak bone mass reduces the risk for osteoporosis later in life. As peak bone mass depends to 20–40 % on lifestyle choices,[1] the behaviour during these years is important for the later health. This process of bone acquisition starts during childhood[2] and the foundations of osteoporosis might lie already there.

Nowadays a generation grows up which is less active than any generation before. Already at an early age there seems to be a tendency of a reduced bone mass in otherwise healthy children. As many children take occasionally or regularly cortisone that, even as spray, leads to a reduction of the bone mass, a catastrophe of bone health might be waiting for us in a few decades.


Today’s children are less active. They do not have the exercises they should have, as for example advised by the WHO (see appendix). Their lives are also characterized by a poverty of motion. There is no variety. Therefore, children are less flexible and balanced. They are not accustomed to use their bodies to solve problems. But they are also not used to use their brains to solve problems, either. Neither today’s parenting, nor the schooling system support problem solving. The poverty of motion and the poverty of thinking are not two independent processes. All research shows that motion and exercise improve cognitive abilities. Motion and exercise improve school success.[3] Motion and exercise make kids smarter.[4] In Greece we have the unfortunate situation that schooling fosters sitting and reading. Motion plays an underpart, if any. The current schooling system is a crime for the pupils, not only for their health, but also for their psychosocial development. An adequate promotion of body exercise and movement would make a major difference.


Motion is important for every organ and every organ has a different story to tell.


The heart begins to beat in the 6th week of gestation, and it continues to beat until death. The long held and wrong assumption of the medical world was that the poor heart should rest a bit if there is some trouble. To treat the heart with care, patients with heart failure had to lie for weeks and were only slowly mobilised. This had not only negative consequences for their muscles and their bones. It had been bad for their hearts, too.[5] Early and vigorous mobilisation is now the rule.

The heart has a tremendous ability to overcome problems. In coronary heart disease it came as a surprise when it was found out that the right exercise has better results than implanting a stent.[6]  Also in peripheral artery disease exercise performs better than implanting a stent.[7] That is, the right training is better than drugs or operations.


It is a wrong idea that we must spare an organ of motion and exercise in order to protect it. Yet this idea still prevails in many problems, e.g., of the tendons, the joints or the spine. Just as with the heart, an adequate exercise is much better than other therapies.


The benefits of exercise for health are numerous. These are but a few examples: Exercise

  • improves diabetes and reduces the insulin resistance,
  • reduces the occurrence of cancer,
  • reduces inflammation and autoimmune diseases,
  • improves hypertension, reduces the probability of stroke and of heart failure,
  • improves and treats depression,
  • prevents neurodegenerative diseases, e.g., Alzheimer disease.

As a result, exercise reduces impressively all-cause mortality.[8]

Impressive is also the impact of motion onto the quality of life. Exercise is probably the best tranquillizer[9] and a very effective antidepressant.[10]

How long should we exercise

The official advice is to have 150 minutes of moderate intensity exercise a week. Moderate intensity exercise means you can talk, but no longer sing.

As with any official advice, we should not take this too literally. It is just a reference point. Just do something. 2 min are better than 0 min.

There are many choices to start with. Start with something simple.

For osteoporosis it is already sufficient just to stand on the toes and then to let the heels plop to the floor. This simple movement creates a percussion in the bones that signalises them that they are still necessary and useful. You also might start with some stretching exercises or might use the skipping rope. All this can be done in a few minutes during office hours. Also, the more complex juggling, with its many health benefits, fits perfectly to a desk job.

How to start

Mostly we want to start exercising because we do not feel well or want to improve something. Some usual reasons are

  • better appearance (increased muscular mass),
  • more strength,
  • loss of weight,
  • improvement of the cardiovascular function and somatic endurance,
  • better cognition and learning abilities,
  • better psychological condition,
  • stress reduction,
  • better balance.

Such aims are called outer or extrinsic motivation. We need a bit of it to start to exercise and to induce a change. The first aim should be to feel good with our practice. The quality of life should slowly increase. Then, whatever we do, becomes part of everyday routine and we just continue because it feels right. This is called inner or intrinsic motivation. This intrinsic motivation is the secret of any effective exercise. It drives us forward. It helps to come out of our comfort zone. It helps us to take the responsibility for ourselves. That is, in order to start exercise, there is no necessity to go compulsively to the gym or the swimming pool. Anything what makes us feel good is perfect to start with. Although even forced exercise is beneficial,[11] forced training mostly diminishes the intrinsic motivation. However, for some of us, inner pressure might be exactly the right thing. Everybody must find an own way to start and continue with an activity.

What kind of exercise should we do?

The kind of exercise we choose depends on the interest, the availability, and the financial abilities. But it is often foremost a question of fantasy. Most people in Heraklion, asked what they might do for their health, cannot imagine something different than going to the gym or to have a walk on the Koule, the historic breakwater. This answer is an expression of the inner poverty, spoken of before. Life is extraordinarily rich. Riding or diving is fine but is difficult to afford. Running is for free, but it might not suit us. To go to the village and cultivate the long-forgotten field is a perfect choice, especially for families. Children playing and working in the field have complex movements, they play and work outside which benefits their Vitamin D, their bronchial system, their bones, and their microbiome. They develop a better relation to food. They train problem solving. And they experience their family tradition. These are but a few of the many benefits of this activity. Other people prefer something more organised like a dancing lessons, pole dance or fencing. Hiking in the Cretan mountains might be done alone, in company or organized in a club. The experience of nature and of freedom is something we rarely have in our everyday life. In the mountains we have this variety everybody needs. The gym, where you might watch TV during exercise, is never able to provide something like that.

Challenge and Failure

The next step is to set new goals, to understand limits and learn to challenge them. The famous trekking path E4 traversing the whole of Crete is a major challenge at hand. It might be done in parts as only very few will do the whole 320 km in one tour.

Unfortunately, just to climb one mountain is more than most people do or even dare to think of. We might do much better than sitting around in coffee shops or taverns.

Crete has many caves. Speleology has simple exercises and caves to start with. We might rediscover this often-forgotten tendency of humans to explore the unknown, the hidden. It might add a new dimension to life. Moreover, it has its own challenges. It is shocking how many people, especially children never felt how it is to challenge the own limits and to go beyond the comfort zone. This is staining their whole lives, often even tainting them.

The gift of failure is one of these charming books explaining how today’s parenting has gone astray.[12] If we want to succeed, we must learn to fail. This is one of the many benefits of extended exercise. We try out something new and we fail. This is a wonderful lesson to strengthen the intrinsic motivation. A similar concern hast the book 50 dangerous things you should let your children do.[13] One of the autor’s conclusion for the development of children is: If you never let them climb a tree, they will eventually do it anyway, possibly in the most unsafe manner possible. Or they may never do it at all, which might be the greater tragedy.

A generation that never climbed a tree has now grown into adulthood and the next generation is not better off. They never knew or forgot that life is a challenge and an adventure, not only a duty. But it is never too late to experience the richness of life. The best practice to rediscover the own vitality is an interesting exercise.

Health and Quality of Life

My attempt to encourage patients to take their health into their hands is often met with reservation. It seems to be difficult, it would require time and effort. Although beginning to exercise is not easy, this is a wrong view. Firstly, such activities provide quality of life. It is won time, not lost time. Secondly, to become ill needs much more time and effort. Thirdly, health, although important, is not even the main point. The topic of motion and exercise poses a very radical question:

What kind of life would you like to live?




WHO Guidelines on Physical Activity for Children under 5 Years of Age.

Infants (less than 1 year) should:

  • Be physically active several times a day in a variety of ways, particularly through interactive floor-based play; more is better. For those not yet mobile, this includes at least 30 minutes in prone position (tummy time) spread throughout the day while awake.
  • Not be restrained for more than 1 hour at a time (e.g. prams/strollers, high chairs, or strapped on a caregiver’s back). Screen time is not recommended. When sedentary, engaging in reading and storytelling with a caregiver is encouraged.

Children 1-2 years of age should:

  • Spend at least 180 minutes in a variety of types of physical activities at any intensity, including moderate-to-vigorous-intensity physical activity, spread throughout the day; more is better.
  • Not be restrained for more than 1 hour at a time (e.g., prams/strollers, high chairs, or strapped on a caregiver’s back) or sit for extended periods of time. For 1-year-olds, sedentary screen time (such as watching TV or videos, playing computer games) is not recommended. For those aged 2 years, sedentary screen time should be no more than 1 hour; less is better. When sedentary, engaging in reading and storytelling with a caregiver is encouraged.

Children 3-4 years of age should:

  • Spend at least 180 minutes in a variety of types of physical activities at any intensity, of which at least 60 minutes is moderate- to vigorous intensity physical activity, spread throughout the day; more is better.

Not be restrained for more than 1 hour at a time (e.g., prams/strollers) or sit for extended periods of time. Sedentary screen time should be no more than 1 hour; less is better. When sedentary, engaging in reading and storytelling with a caregiver is encouraged.

[1] Weaver CM, Gordon CM, Janz KF, et al. The National Osteoporosis Foundation’s position statement on peak bone mass development and lifestyle factors: a systematic review and implementation recommendations [published correction appears in Osteoporos Int. 2016 Apr;27(4):1387]. Osteoporos Int. 2016;27(4):1281-1386. doi:10.1007/s00198-015-3440-3

[2] Davies JH, B Evans BA, Gregory JW (2005): Bone mass acquisition in healthy children, Archives of Disease in Childhood 2005;90:373-378

[3] Raine LB, Lee HK, Saliba BJ, Chaddock-Heyman L, Hillman CH, Kramer AF (2013) The Influence of Childhood Aerobic Fitness on Learning and Memory. PLoS ONE 8(9): e72666. https://doi.org/10.1371/journal.pone.0072666

[4] Chaddock L, Erickson KI, Prakash RS, VanPatter M, Voss MW, Pontifex MB, Raine LB, Hillman CH, Kramer AF. Basal ganglia volume is associated with aerobic fitness in preadolescent children. Dev Neurosci. 2010 Aug;32(3):249-56. doi: 10.1159/000316648. Epub 2010 Aug 6. PMID: 20693803; PMCID: PMC3696376

[5] Wisløff U, Støylen A (2007): Superior Cardiovascular Effect of Aerobic Interval Training Versus Moderate Continuous Training in Heart Failure Patients, Circulation. 2007;115:3086–3094

[6] Hambrecht R, Walther C, Möbius-Winkler S, Gielen S, Linke A, Conradi K, Erbs S, Kluge R, Kendziorra K, Sabri O, Sick P, Schuler G (2004): Percutaneous coronary angioplasty compared with exercise training in patients with stable coronary artery disease: a randomized trial, Circulation 109; 11:1371-8

[7] Murphy TP, Cutlip DE (2011): Supervised Exercise Versus Primary Stenting for Claudication Resulting From Aortoiliac Peripheral Artery Disease, Circulation. 2012;125:130–139


[8] U.S. Department of Health & Human Services (2018) Physical Activity Guidelines Advisory Committee Scientific Report F6.-8. p. 359


[9] Schoenfeld TJ, Rada P, Pieruzzini PR, Hsueh B, Gould E. Physical exercise prevents stress-induced activation of granule neurons and enhances local inhibitory mechanisms in the dentate gyrus. J Neurosci. 2013 May 1;33(18):7770-7. doi: 10.1523/JNEUROSCI.5352-12.2013. PMID: 23637169; PMCID: PMC3865561.

[10] Morres, ID, Hatzigeorgiadis, A, Stathi, A, et al. Aerobic exercise for adult patients with major depressive disorder in mental health services: A systematic review and meta‐analysis. Depress Anxiety. 2019; 36: 39– 53. https://doi.org/10.1002/da.22842

[11] Greenwood BN, Spence KG, Crevling DM, Clark PJ, Craig WC, Fleshner M. Exercise-induced stress resistance is independent of exercise controllability and the medial prefrontal cortex. Eur J Neurosci. 2013 Feb;37(3):469-78. doi: 10.1111/ejn.12044. Epub 2012 Nov 4. PMID: 23121339; PMCID: PMC4285393.

[12] Lahey J (2015): The Gift of Failure, New York

[13] Tulley G (2011): 50 dangerous things you should let your children do, Berkley