Some Other Important Numbers or "Sailor, Get Off Your Kiester"¹
“A healthy mind in a healthy body” is a phrase attributed to the Greek poet Thales, a 6th century BCE, pre-Socratic philosopher. Ah, the Greeks. We should have paid more attention to them. We borrowed from them the concept of democracy, but we neglected a fundamental principle of Greek life – “A healthy mind in a healthy body.”
Of course, we are all aware of the Olympic Games but more than an occasional sporting event, the classical Greeks considered mental life and physical life to be two sides of the same coin. Physical training was considered a civic duty rather than any kind of lifestyle choice. Training facilities and even professional trainers were provided by the city for champion athletes as well as ordinary citizens! [2] In fact, athletic training (Greek sports science) was equal in status to medicine. Hippocrates and Galen, physicians of enormous influence, actually observed athletes while they trained in order to better understand the human body; and they developed anatomical and nutritional guides to improve performance. Aristotle wrote detailed coaching manuals and Galen stated that doctors should train like athletes to achieve excellence in their practice.
A training regimen in ancient Greece included three components: a warmup, the training, and then the cool down exactly in line with the American Heart Association. [3] There were a range of options for the main workout including whole body workouts, zone workouts, or training geared toward a specific sport such as boxing or wrestling (using punching bags and shadow boxing. There were various techniques to strengthen the upper body and various running exercises including high resistance running through the sand.
The key is that they worked out frequently, often daily, and it was an essential part of their day.[4]
It took us well over two thousand years, but we humans are picking up where the Greeks left off. Finally, with the latest guidelines there is a consensus that we need to move; no not just exercises but we also need to diminish our sedentary time. It is killing us.
What is the scope of the problem? In the US, about half of all American adults – 117 million – have one or more preventable chronic diseases and 7/10 of the most common chronic diseases will benefit from regular physical activity. Yet nearly 80% are not meeting the key guidelines for aerobic and strength training activity.
Three publications have come out in the last couple of years and all three with minor variations contain similar recommendations or guidelines (and all are available on-line):
Physical Activity Guidelines for Americans, 2nd edition
UK Chief Medical Officers Physical Activity Guidelines
World Health Organization 2020 Guidelines On Physical Activity and Sedentary Behavior
All three now have specific recommendations for
Children and Adolescents
Adults
Older Adults
Pregnant and Postpartum Women
Adults with Chronic Health Conditions and / or Disabilities
I am going to stick with the Adult guidelines. Please consult any of the three guidelines if you fall under a different category. The key adult guidelines are as follows:
Adults should move more and sit less throughout the day. Some physical activity is better than none. Adults who sit less and do any amount of moderate-to-vigorous physical activity gain some health benefits.
For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the week.
Additional health benefits are gained by engaging in physical activity beyond the equivalent of 300 minutes (5 hours) of moderate-intensity physical activity a week.
Adults should also do muscle-strengthening activities of moderate or greater intensity and that involve all major muscle groups on 2 or more days a week, as these activities provide additional health benefits.
These are summarized in the following illustration:
What are the benefits? The evidence continues to mount for the benefits of physical activity – which probably would not have surprised any of the ancient Greeks! Here are some quotes from Hippocrates:
“If we could give every individual the right amount of nourishment and exercise, not too much, we would have found the safest way to health”.
“Walking is the best medicine”.
“That which is used develops, and that which is not used wastes away. If there is any deficiency in exercise the body will become liable to disease, defective in growth and age quickly”.
“Eating alone will not keep a man well; he must also take exercise. For food and exercise work together to produce health”. (see endnote #2; Greek exercise was strictly a male affair)
“If you are in a bad mood go for a walk. If you are still in a bad mood go for another walk”.
In the table below is listed the “new” evidence of physical activity benefits:
Evidence from the UK report:
Any exercise is better than no exercise and the UK report contains a “dose-response” graph which illustrates that the highest impact on health is the initial increase in activity. Notice how steep the initial portion of the curve is. In other words, just getting off your keister and getting started is most important!
OK, so most of us are aware that sedentary behavior, which involves sitting, reclining, or lying is consistently linked to more than thirty chronic diseases and conditions including a 147% increase in heart disease risk and a 112% increase in the risk of type 2 diabetes mellitus.[5], [6]
In fact, the people with the most sedentary behavior had a 22-49% greater risk of early death.
So, in the words of an old African American spiritual… “You Gotta Move.” [7]
How rapidly does sedentary behavior begin to produce a decline? One study evaluated healthy, non-exercising individuals who went from a normal to a low level of ambulatory activity for a 2-week period.[8] These subjects decreased their daily activity level as part of the study from a mean of 10,000 steps to less than 1,500 steps per day. A reduced number of daily steps impaired insulin sensitivity, reduced lean muscle mass, and produced a 7% decline in VO2 max. As we saw in the prior blog (“One Number Every Sailor Should Know”) VO2 max is an excellent indicator of overall cardiovascular fitness – and a 7% decline in just two weeks of reduced activity is impressive and frightening!
Does the exercise have to be moderately vigorous to help to counteract prolonged sitting? No, but realistically most of us don’t have hours of standing and walking which is what it would take to counteract the sedentary lifestyle. Two recent studies compared the effect of prolonged standing and sitting with moderate to vigorous exercise, about an hour per day of cycling. [9] , [10] These studies reported that the standing and walking for many hours produced a better result (in terms of glucose control and insulin sensitivity) than brief moderate to vigorous intensity cycling. So, replacing sitting with standing (hence the popularity of the standing desk) and walking appears to have great benefit and of course it also will help you burn calories. But who has the hours and hours each day to avoid sitting? Most of us don’t have the luxury. [Please refer to the discussion in the book [11] concerning NEAT (non-exercise activity thermogenesis).]
Almost certainly the activity of standing and walking as well as other activities which require frequent motion – and little sitting – is responsible in part for the longevity of those communities around the world referred to as The Blue Zones, where inhabitants routinely live into their 90s and 100s. [12]
Blue Zones
But what about those of us who have sedentary jobs and cannot possibly integrate hours of standing and walking? Can we offset the effects of prolonged sitting with moderate to vigorous physical activity (MVPA)? And if so, how much activity does it take?
A study of 1 million men and women addressing just this point was published in 2016; the title was “Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality” [13] The answer according to this huge study was that high levels of moderate intensity physical activity (i.e. about 60-75 minutes per day) seemed to eliminate the increased risk of death associated with high sitting time. Lesser degrees of activity i.e. about 25-35 minutes of moderate activity did produce smaller risk reductions. So, if you sit for 8 hours per day, the only way to eliminate the sitting risk is to devote 60-75 minutes per day in moderate to vigorous physical activity (MVPA).
As one who has always done about 30-40 minutes of MVPA per day, that is downright discouraging!
But, in 2020 Dr. Ekelund et al. looked at the same problem again, but this time required that the physical activity and sedentary time be accelerometer-measured rather than by personal recollection. [14] Their results indicated that the about 30-40 minutes of MVPA per day attenuate the association between sedentary time and risk of death – lower than prior estimates from self-reported data. So, if you must be sedentary (and some of us must!) then go ahead and find that 30-40 minutes and just do it!
Finally, in addition to specifically targeting sedentary activity as problematic, each of the three guidelines discuss the need for strength training. The US, UK, and WHO guidelines recommend 2 days a week should be spent in strength (resistance) training that involves all major muscle groups. See the figure above entitled “Move Your Way.”
This should be considerably easier for us than for the ancient Greeks. While we have multiple options including Universal-type gym equipment, barbells, dumbbells, kettlebells, resistance bands, etc., the Greeks had to content themselves with bending or straightening metal bars, lifting stones of various sizes, lifting heavy rocks, pulling carts or ploughs, and lifting animals such as horses and bulls.
If all of the above discussion didn’t motivate you to get moving, then at least the next time you gaze upon a classic Greek urn you will realize that those sculpted abs and glutes were not a result of artistic license. They were earned the hard way!
[1] For our British sailors, a “kiester” is your “bum” - but you guessed that
[2] And by “citizens” I am of course referring to male citizens. The gymnasium, from which we get the term “gym” was exclusively a male endeavor except in Sparta where women were expected to work out separately.
[3] https://www.heart.org/en/healthy-living/fitness/fitness-basics/warm-up-cool-down
[4] Of course, it helped that most Greek citizens had slaves and other assistants to do most of the work, allowing them the time to work out. They never had to cancel a workout in order to write an important memo.
[5] Sedentary Time and Its Association with Risk…Biswas, Oh, et al. Annals of Internal Medicine, 20 January 2015 doi.org/10.7326/M14-1651
[6] Wilmot et al. Diabetologia November 2012
[7] Traditional song with exceptional renditions by Sister Rosetta Tharpe, Original Blind Boys of Alabama, and Reverend Gary Davis.
[8] Krogh-Madsen et al “A 2-wk reduction of ambulatory activity attenuates peripheral insulin sensitivity, L Appl Physiol, 2010 doi:10.1152/japplphysiol.0977.2009.Epub 2009 December 31
[9] Duvivier, Schaper, et al. Minimal Intensity Physical Activity (Standing and Walking) of Longer Duration…www.plosone.org 8(2): e55542 doi:10.1371/journal.pone.0055542
[10] Duvivier, Schaper, et al. Breaking Sitting with Light Activities vs. Structured Exercise…Diabetologia (2017) 60: 490-498
[11] Healthy Boating and Sailing, the author
[12] Ikaria, Greece; Okinawa, Japan; Ogliastra Region of Sardinia; Loma Linda, California; Nicoya Peninsula, Costa Rica are the classic five. Also, their diet – less food, more fruits and vegetables, healthy fats, positive attitude and socialization, and probably their genes!
[13] Ekelund, et al. Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? Lancet 2016; 388:1302-10 doi.org/10.1016/50140-6736(16)30370-1
[14] Personal medical observation: People invariably report double the amount of physical activity they actually do and halve the amount of alcohol they actually drink.