NOTES

Introduction

1. 1. For an overview of hunter-gatherers, please see Emma Groeneveld, “Prehistoric Hunter-Gatherer Societies,” Ancient History Encyclopedia (December 9, 2016), https://www.ancient.eu/article/991/prehistoric-hunter-gatherer-societies/.
2. 2. These dates are approximate. See Graeme Barker, The Agricultural Revolution in Prehistory: Why did Foragers become Farmers? (Oxford; New York: Oxford University Press, 2006), 13–29 et passim for a history of dating.
3. 3. Leon Kreitzman, “How the 24-hour Society Is Stealing Time from the Night,” Aeon, November 22, 2016, https://aeon.co/ideas/how-the-24-hour-society-is-stealing-time-from-the-night; “Effects of the Industrial Revolution,” Modern World History (interactive textbook), accessed September 11, 2019, https://webs.bcp.org/sites/vcleary/ModernWorldHistoryTextbook/IndustrialRevolution/IREffects.html.
4. 4. See, for example, Peter Just, “Time and Leisure in the Elaboration of Culture,” Journal of Anthropological Research 36, no. 1 (Spring 1980): 105–15.
5. 5. Signe Dean, “Every Single Cell in Your Body Is Controlled by Its Own Circadian Clock,” Science Alert (October 2, 2015), https://www.sciencealert.com/your-body-has-trillions-of-clocks-in-its-cells; Flávia Dourado, “Discerning the Biological Clock of Single-Celled Organisms,” Institute of Advanced Studies of the University of São Paulo, May 27, 2015, http://www.iea.usp.br/en/news/single-celled-organisms.
6. 6. For more on Frankl’s philosophy about happiness and purpose, please see Emily Esfahani Smith, “There’s More to Life Than Being Happy,” Atlantic, January 9, 2013, https://www.theatlantic.com/health/archive/2013/01/theres-more-to-life-than-being-happy/266805/.
7. 7. Thomas Paine, Thomas Paine: Major Works (Lulu.com, 2017), 601.
8. 8. Michael Pollan’s In Defense of Food: An Eater’s Manifesto (New York: Penguin Press, 2008) is a great place to start.
9. 9. Maslow later nuanced and clarified his thinking about satisfying lower-order needs and ascending the hierarchy. Please see my discussion below and Saul McLeod, “Maslow’s Hierarchy of Needs,” Simple Psychology, updated 2018, https://www.simplypsychology.org/maslow.html.

Chapter One: Beaten Down by Being Normal

1. 1. “Does Your Body Temperature Change While You Sleep?,” sleep.org (National Sleep Foundation), accessed September 12, 2019, https://www.sleep.org/articles/does-your-body-temperature-change-while-you-sleep/.
2. 2. Ibid.
3. 3. Ibid.
4. 4. Ibid.
5. 5. Vijay Kumar Sharma and M. K. Chandrashekaran, “Zeitgebers (time cues) for Biological Clocks,” Current Science 89, no. 7 (October 2005): 1136–46.
6. 6. For the harmful effect of disease, please see “Blue Light Has a Dark Side,” Harvard Health Publishing, updated August 13, 2018, https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side.
7. 7. Ganda Suthivarakom, “Share a Bed Without Losing Sleep,” New York Times, March 18, 2019, https://www.nytimes.com/2019/03/18/smarter-living/wirecutter/how-to-share-bed-sleep-partner.html.
8. 8. Ibid.
9. 9. William J. Cromie, “Human Biological Clock Set Back an Hour,” Harvard Gazette, July 15, 1999, https://news.harvard.edu/gazette/story/1999/07/human-biological-clock-set-back-an-hour/.
10. 10. Sujana Reddy and Sandeep Sharma, “Physiology, Circadian Rhythm,” StatPearls, updated October 27, 2018, https://www.ncbi.nlm.nih.gov/books/NBK519507/; Willemijntje A. Hoogerwerf, “Role of Clock Genes in Gastrointestinal Motility,” American Journal of Physiology-Gastrointestinal and Liver Physiology 299, no. 3, September 2010, doi: 10.1152/ajpgi.00147.2010.
11. 11. Paloma Cantero-Gomez, “From Time to Energy Management or How to Learn the Art of Living,” Forbes, October 24, 2018, https://www.forbes.com/sites/palomacanterogomez/2018/10/24/from-time-to-energy-management-or-how-to-learn-the-art-of-living/#5e3452e97e14.
12. 12. Ibid.
13. 13. Alice G. Walton, “Your Body’s Internal Clock and How It Affects Your Overall Health,” Atlantic, March 20, 2012, https://www.theatlantic.com/health/archive/2012/03/your-bodys-internal-clock-and-how-it-affects-your-overall-health/254518/; Jonathan Fahey, “How Your Brain Tells Time,” Forbes, October 15, 2009, https://www.forbes.com/2009/10/14/circadian-rhythm-math-technology-breakthroughs-brain.html#276b8ffe3fa7.
14. 14. Alice G. Walton, “Your Body’s Internal Clock and How It Affects Your Overall Health.”
15. 15. Ibid.
16. 16. Ibid.
17. 17. “Melatonin and Sleep,” National Sleep Foundation, accessed March 27, 2019, https://www.sleepfoundation.org/articles/melatonin-and-sleep.
18. 18. Some call it the “Dracula of hormones”: “Melatonin and Sleep.”
19. 19. “Melatonin and Sleep,” National Sleep Foundation.
20. 20. Kewin Tien Ho Siah, Reuben Kong Min Wong, and Khek Yu Ho, “Melatonin for the Treatment of Irritable Bowel Syndrome,” World Journal of Gastroenterology 20, no. 10 (March 2014), doi: 10.3748/wjg.v20.i10.2492; Reza Sharafati-Chaleshtori et al., “Melatonin and Human Mitochondrial Diseases,” Journal of Research in Medical Sciences 22, no. 2 (January 2017), doi: 10.4103/1735-1995.199092; Antonio Carrillo-Vico et al., “A Review of the Multiple Actions of Melatonin on the Immune System,” Endocrine 27, no. 2 (July 2005): 189–200; Kavita Beri & Sandy Saul Milgraum, “Rhyme and Reason: The Role of Circadian Rhythms in Skin and Its Implications for Physicians,” Future Science 2, no. 2 (April 2016), https://doi.org/10.4155/fsoa-2016–0007.
21. 21. Thomas A. Wehr, “Melatonin and Seasonal Rhythms,” Journal of Biological Rhythms 12, no. 6 (December 1997): 518–27, https://doi.org/10.1177/074873049701200605.
22. 22. Michael J. Kuhar, Pastor R. Couceyro, and Philip D. Lambert, “Biosynthesis of Catecholamines,” in Basic Neurochemistry: Molecular, Cellular and Medical Aspects 6th ed., G.J. Siegel et al., eds. (Philadelphia: Lippincott-Raven, 1999), available from: https://www.ncbi.nlm.nih.gov/books/NBK27988/.

Chapter Two: It Starts with Sleep

1. 1. P. B. Laursen, “Training for Intense Exercise Performance: High-Intensity or High-Volume Training?” Scandinavian Journal of Medicine & Science in Sports 20 supplement 2 (October 2010): 1–10, doi: 10.1111/j.1600-0838.2010.01184.x; M. Wewege et al., “The Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Body Composition in Overweight and Obese Adults: A Systematic Review and Meta-Analysis,” Obesity Reviews 18, no. 6 (June 2017): 635–46, https://doi.org/10.1111/obr.12532; Micah Zuhl and Len Kravitz, “HIIT vs. Continuous Endurance Training: Battle of the Aerobic Titans,” accessed September 13, 2019, https://www.unm.edu/~lkravitz/Article%20folder/HIITvsCardio.html.
2. 2. Morgan Manella, “Study: A Third of U.S. Adults Don’t Get Enough Sleep,” CNN, updated February 18, 2016, https://www.cnn.com/2016/02/18/health/one-third-americans-dont-sleep-enough/index.html.
3. 3. Neil Howe, “America the Sleep-Deprived,” Forbes, August 18, 2017, https://www.forbes.com/sites/neilhowe/2017/08/18/america-the-sleep-deprived/#38559f0e1a38.
4. 4. Ibid.
5. 5. Gandhi Yetish et al., “Natural Sleep and Its Seasonal Variations in Three Pre-industrial Societies,” Current Biology 25, no. 21 (November 2015), doi: https://doi.org/10.1016/j.cub.2015.09.046.
6. 6. Ibid.
7. 7. Meg Sullivan, “Our Ancestors Probably Didn’t Get 8 Hours a Night, Either,” UCLA Newsroom (October 15, 2015), http://newsroom.ucla.edu/releases/our-ancestors-probably-didnt-get-8-hours-a-night-either.
8. 8. Ibid.
9. 9. A conclusion that Richard G. “Bugs” Stevens, professor of medicine at the University of Connecticut, arrived at as well: “We Don’t Need More Sleep. We Just Need More Darkness,” Washington Post, October 27, 2015, https://www.washingtonpost.com/posteverything/wp/2015/10/27/we-dont-need-more-sleep-we-just-need-more-darkness/?noredirect=on.
10. 10. Ibid.
11. 11. See this revealing profile for more: Linda Geddes, “What I Learned by Living without Artificial Light,” BBC (April 25, 2018), http://www.bbc.com/future/story/20180424-what-i-learnt-by-living-without-artificial-light.
12. 12. “Why Americans Can’t Sleep,” Consumer Reports, updated January 14, 2016, https://www.consumerreports.org/sleep/why-americans-cant-sleep/.
13. 13. See the National Optical Astronomy Observatory’s (NOAO) figures and recommended illumination thresholds for various indoor spaces: “Recommended Light Levels,” accessed September 13, 2019, https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf.
14. 14. For all the facts and figures related to Linda Geddes, I relied on Geddes, What I Learned by Living without Artificial Light.”
15. 15. Lorenzo Lazzerini Ospri, Glen Prusky, and Samer Hattar, “Mood, the Circadian System, and Melanopsin Retinal Ganglion Cells,” Annual Review of Neuroscience 40 (July 2017): 539–56, https://doi.org/10.1146/annurev-neuro-072116-031324.
16. 16. Haruna Fukushige et al., “Effects of Tryptophan-Rich Breakfast and Light Exposure During the Daytime on Melatonin Secretion at Night,” Journal of Physiological Anthropology 33 (November 2014), doi: 10.1186/1880-6805-33-33.
17. 17. T. Kozaki et al., “Light-Induced Melatonin Suppression at Night After Exposure to Different Wavelength Composition of Morning Light,” Neuroscience Letters 616 (March 2016), doi: 10.1016/j.neulet.2015.12.063.
18. 18. B. S. Alghamdi, “The Neuroprotective Role of Melatonin in Neurological Disorders,” Journal of Neuroscience Research 96, no. 7 (July 2018): 1136–49, doi: 10.1002/jnr.24220.
19. 19. Y. Li et al., “Melatonin for the Prevention and Treatment of Cancer,” Oncotarget 8, no. 24 (June 2017), doi: 10.18632/oncotarget.16379.
20. 20. G. J. Elder et al., “The Cortisol Awakening Response—Applications and Implications for Sleep Medicine,” Sleep Medicine Reviews 18, no. 3 (June 2014): 215–24, doi: 10.1016/j.smrv.2013.05.001.
21. 21. Michelle Dickinson, “Nanogirl Michelle Dickinson: Are Dim Lights Making Us Dimmer?” NZ Herald, February 10, 2018, https://www.nzherald.co.nz/lifestyle/news/article.cfm?c_id=6&objectid=11990507.
22. 22. Elie Dolgin, “The Myopia Bboom,” Nature (March 18, 2015), https://www.nature.com/news/the-myopia-boom-1.17120.
23. 23. R. W. Lam et al., “L-Tryptophan Augmentation of Light Therapy in Patients with Seasonal Affective Disorder,” Canadian Journal of Psychiatry 42, no. 3 (April 1997): 303–6; Sherri Melrose, “Seasonal Affective Disorder: An Overview of Assessment and Treatment Approaches,” Depression Research and Treatment (November 2015), doi: 10.1155/2015/178564.
24. 24. J. M. Booker and C. J. Hellekson, “Prevalence of Seasonal Affective Disorder in Alaska,” American Journal of Psychiatry 149, no. 9 (September 1992): 1176–82; S. Saarijärvi et al., “Seasonal Affective Disorders Among Rural Finns and Lapps,” Acta Psychiatrica Scandinavica 99, no. 2 (February 1999): 95–101.
25. 25. Kathryn A. Roecklein and Kelly J. Rohan, “Seasonal Affective Disorder,” Psychiatry (Edgmont) 2, no. 1 (January 2005): 20–26.
26. 26. “Seasonal Affective Disorder (SAD),” Mayo Clinic, accessed September 18, 2019, https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/symptoms-causes/syc-20364651.
27. 27. Alice Park, “Why Sunlight Is So Good For You,” Time, August 7, 2017, https://time.com/4888327/why-sunlight-is-so-good-for-you/; Christopher M. Jung et al., “Acute Effects of Bright Light Exposure on Cortisol Levels,” Journal of Biological Rhythms 25, no. 3 (June 2010): 208–16, doi: 10.1177/0748730410368413; H.Y. Tsai et al., “Sunshine-Exposure Variation of Human Striatal Dopamine D(2)/D(3) Receptor Availability in Healthy Volunteers,” Progress in Neuro-Psychopharmacology & Biological Psychiatry 35, no. 1 (January 2011): 107–10, doi: 10.1016/j.pnpbp.2010.09.014.

Chapter Three: Food Doesn’t Have to Be So Hard

1. 1. Jared Diamond, “The Worst Mistake in the History of the Human Race,” Discover, 1987: 95–98.
2. 2. M. E. Zaki, F. H. Hussien, and R. Abd El-Shafy El Banna, “Osteoporosis Among Ancient Egyptians,” International Journal of Osteoarchaeology 19, no. 1 (January–February 2009): 78–89, https://doi.org/10.1002/oa.978; Rebecca Hersher, “Mummified Egyptian Was Just As Sedentary and Carb-Hungry As Modern Men,” NPR (July 26, 2016), https://www.npr.org/sections/thetwo-way/2016/07/26/487505112/mummified-egyptian-was-just-as-sedentary-and-carb-hungry-as-modern-men.
3. 3. V. Lobo et al., “Free Radicals, Antioxidants and Functional Foods: Impact on Human Health,” Pharmacognosy Review 4, no. 8 (2010): 118–26; Megan Ware, “How Can Antioxidants Benefit Our Health?” Medical News Today, updated May 29, 2018, https://www.medicalnewstoday.com/articles/301506.php.
4. 4. Please see Dallas Hartwig and Melissa Hartwig, It Starts with Food (Las Vegas: Victory Belt Publishing Inc., 2012), 113–16.
5. 5. Aleksandra Crapanzano, “How Eating More of What You Love Can Make You Healthier,” Wall Street Journal, May 2, 2019, https://www.wsj.com/articles/how-eating-more-of-what-you-love-can-make-you-healthier-11556822538.
6. 6. Ibid.
7. 7. This material is reproduced from my website dallashartwig.com.
8. 8. See, for example, E. A. Martens, S. G. Lemmens, and M. S. Westerterp-Plantenga, “Protein Leverage Affects Energy Intake of High-Protein Diets in Humans,” American Journal of Clinical Nutrition 97, no. 1 (January 2013): 86–93, doi: 10.3945/ajcn.112.046540; Stephen J. Simpson and David Raubenheimer, “Tricks of the Trade,” Nature 508 (April 17, 2014).
9. 9. Alison K. Gosby et al., “Protein Leverage and Energy Intake,” Obesity Reviews 15, no. 3 (March 2014): 183–91, https://doi.org/10.1111/obr.12131.
10. 10. Alison K. Gosby et al., “Testing Protein Leverage in Lean Humans: A Randomised Controlled Experimental Study,” PLOS One (October 12, 2011).
11. 11. Ibid.
12. 12. G. A. Hendrie et al., “Greenhouse Gas Emissions and the Australian Diet—Comparing Dietary Recommendations with Average Intakes,” Nutrients 6, no. 1 (January 2014): 289–303, doi: 10.3390/nu6010289.
13. 13. Shubhroz Gill and Satchidananda Panda, “A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits,” Cell Metabolism 22, no. 5 (November 2015): 789–98, doi: 10.1016/j.cmet.2015.09.005; Amandine Chaix et al., “Time-Restricted Feeding Prevents Obesity and Metabolic Syndrome in Mice Lacking a Circadian Clock,” Cell Metabolism 29, no. 2 (February 2019), doi: https://doi.org/10.1016/j.cmet.2018.08.004; Satchidananda Panda, The Circadian Code: Lose Weight, Supercharge Your Energy, and Transform Your Health from Morning to Midnight (New York: Rodale, 2018).
14. 14. Anahad O’Connor, “When We Eat, or Don’t Eat, May Be Critical for Health,” New York Times, July 24, 2018, https://www.nytimes.com/2018/07/24/well/when-we-eat-or-dont-eat-may-be-critical-for-health.html.
15. 15. Ibid.
16. 16. See, for example, R. J. Jarrett et al., “Diurnal Variation in Oral Glucose Tolerance: Blood Sugar and Plasma Insulin Levels Morning, Afternoon, and Evening,” British Medical Journal 1 (January 1972): 199–201, doi: 10.1136/bmj.1.5794.199; Eve Van Cauter, Kenneth S. Polonsky, and André J. Scheen, “Roles of Circadian Rhythmicity and Sleep in Human Glucose Regulation,” Endocrine Reviews 18, no. 5 (October 1997): 716–38, https://doi.org/10.1210/edrv.18.5.0317; Christopher J. Morris et al., “Endogenous Circadian System and Circadian Misalignment Impact Glucose Tolerance Via Separate Mechanisms in Humans,” Proceedings of the National Academy of Sciences of the United States of America 112, no. 17 (April 2015), doi: 10.1073/pnas.1418955112.
17. 17. Dan Buettner, “Reverse Engineering Longevity,” Blue Zones, accessed September 13, 2019, https://www.bluezones.com/2016/11/power-9/.
18. 18. “Social eating connects communities,” University of Oxford (March 16, 2017), http://www.ox.ac.uk/news/2017-03-16-social-eating-connects-communities#.
19. 19. Shankar Vedantam, “Why Eating the Same Food Increases People’s Trust and Cooperation,” NPR (February 2, 2017), https://www.npr.org/2017/02/02/512998465/why-eating-the-same-food-increases-peoples-trust-and-cooperation.
20. 20. Michael Pollan estimates 20 percent in a Stanford profile, and 19 percent in an interview with Grist: “What’s for Dinner?” Stanford University, accessed September 14, 2019, https://news.stanford.edu/news/multi/features/food/eating.html; “An Interview with Foodie Author Michael Pollan,” Grist, May 31, 2006, https://grist.org/article/roberts7/.
21. 21. Based on data gathered between 2013 and 2016: Jamie Ducharme, “Almost 40% of Americans Eat Fast Food on Any Given Day, Report Says,” Time, October 3, 2018, https://time.com/5412796/fast-food-americans/.
22. 22. Leslie Krohn, “Family Dinner Time? Better Leave the Cell Phone Behind,” Harris Poll (June 7, 2016), https://theharrispoll.com/family-dinners-have-customarily-held-a-sacred-place-as-part-of-family-life-holidays-and-traditions-but-what-do-they-look-like-to-americans-today-to-better-understand-what-modern-family-di/.

Chapter Four: Moving to the Rhythm

1. 1. Jacqueline Howard, “Americans Devote More than 10 Hours a Day to Screen Time, and Growing,” CNN (July 29, 2016), https://www.cnn.com/2016/06/30/health/americans-screen-time-nielsen/index.html.
2. 2. Lindsey Tanner, “Americans Getting More Inactive, Computers Partly to Blame,” WGBH (April 23, 2019), https://www.wgbh.org/news/science-and-technology/2019/04/23/americans-getting-more-inactive-computers-partly-to-blame.
3. 3. Susan Scutti, “Yes, Sitting Too Long Can Kill You, Even If You Exercise,” CNN, updated September 12, 2017, https://www.cnn.com/2017/09/11/health/sitting-increases-risk-of-death-study/index.html. See also Keith M. Diaz et al., “Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults: A National Cohort Study,” Annals of Internal Medicine 167, no. 7 (September 2017): 465–75, doi: 10.7326/M17-0212.
4. 4. Jamie Ducharme, “A Quarter of the World’s Adults Don’t Get Enough Exercise, Study Says,” Time, September 5, 2018, http://time.com/5387221/who-physical-inactivity-report/.
5. 5. Gretchen Livingston, “The Way U.S. Teens Spend Their Time Is Changing, But Differences Between Boys and Girls Persist,” Pew Research Center (February 20, 2019), https://www.pewresearch.org/fact-tank/2019/02/20/the-way-u-s-teens-spend-their-time-is-changing-but-differences-between-boys-and-girls-persist/.
6. 6. Associated Press, “Kids Today Are Less Fit Than Their Parents Were,” Washington Post, November 25, 2013, https://www.washingtonpost.com/national/health-science/kids-today-are-less-fit-than-their-parents-were/2013/11/25/8ecb1f0a-515f-11e3-9fe0-fd2ca728e67c_story.html?utm_term=.9c9de67571fc.
7. 7. Jacob Bogage, “Youth Sports Still Struggling With Dropping Participation, High Costs and Bad Coaches, Study Finds,” Washington Post, October 16, 2018, https://beta.washingtonpost.com/sports/2018/10/16/youth-sports-still-struggling-with-dropping-participation-high-costs-bad-coaches-study-finds/.
8. 8. Associated Press, “Kids Today Are Less Fit Than Their Parents Were.”
9. 9. Ibid.
10. 10. “To Grow Up Healthy, Children Need to Sit Less and Play More,” World Health Organization (April 24, 2019), https://www.who.int/news-room/detail/24-04-2019-to-grow-up-healthy-children-need-to-sit-less-and-play-more.
11. 11. Katy Bowman, Movement Matters: Essays on Movement Science, Movement Ecology, and the Nature of Movement (Washington: Propriometrics Press, 2016).
12. 12. Peter Beech, “Hard Living: What Does Concrete Do to Our Bodies?” Guardian, February 28, 2019, https://www.theguardian.com/cities/2019/feb/28/hard-living-what-does-concrete-do-to-our-bodies.
13. 13. Ibid.
14. 14. “Osteoporosis Fast Facts,” National Osteoporosis Foundation, accessed May 14, 2019, https://cdn.nof.org/wp-content/uploads/2015/12/Osteoporosis-Fast-Facts.pdf.
15. 15. See Table 2 in James H. O’Keefe et al., “Achieving Hunter-Gatherer Fitness in the 21(st) Century: Back to the Future,” American Journal of Medicine 123, no. 12 (December 2010): 1082–6, doi: 10.1016/j.amjmed.2010.04.026.
16. 16. Svenia Schnyder and Christoph Handschin, “Skeletal Muscle as an Endocrine Organ: PGC-1 a, myokines and exercise,” Bone 80 (November 2015): 115–25, doi: 10.1016/j.bone.2015.02.008.
17. 17. Adam Campbell, “The Stupidest Thing People Say about Diet and Exercise,” Men’s Health, September 30, 2015, https://www.menshealth.com/fitness/a19524094/stupidest-thing-people-say-diet-exercise/.
18. 18. “Physical Activity Guidelines for Americans,” US Department of Health & Human Services, accessed May 14, 2019, https://www.hhs.gov/fitness/be-active/physical-activity-guidelines-for-americans/index.html.
19. 19. “Physical Activity Guidelines for Americans” (second edition), health.gov, https://health.gov/paguidelines/second-edition/pdf/Physical_Activity_Guidelines_2nd_edition.pdf, 8.
20. 20. Gabriella Boston, “Fitness through the Ages,” Chicago Tribune, September 4, 2013, https://www.chicagotribune.com/lifestyles/ct-xpm-2013-09-04-sc-health-0904-fitness-aging-20130904-story.html.
21. 21. Talisa Emberts et al., “Exercise Intensity and Energy Expenditure of a Tabata Workout,” Journal of Sports Science & Medicine 12, no. 3 (September 2013): 612–13.
22. 22. Gretchen Reynolds, “The Best Type of Exercise to Burn Fat,” New York Times, February 27, 2019, https://www.nytimes.com/2019/02/27/well/move/the-best-type-of-exercise-to-burn-fat.html.
23. 23. Stephen Seiler, “What is Best Practice for Training Intensity and Duration Distribution in Endurance Athletes?” International Journal of Sports Physiology and Performance 5 (2010): 276, 282.
24. 24. For more on Dr. Heke, please see the Ancestral Health Society of New Zealand’s “Atua to Matua: Maori ‘Ecology and the Connection to Health and Physical Activity,’ ” YouTube video, 45.31, posted January 13, 2016, https://www.youtube.com/watch?v=GjIY0Fka3TY&t=23s.
25. 25. The remainder of this section borrows heavily from my website, dallashartwig.com.
26. 26. Melinda M. Gardner, M. Clare Robertson, and A. John Campbell, “Exercise in Preventing Falls and Fall Related Injuries in Older People: A Review of Randomised Controlled Trials,” British Journal of Sports Medicine 34, no. 1 (2000): 7–17; Seong-Il Cho and Duk-Hyun An, “Effects of a Fall Prevention Exercise Program on Muscle Strength and Balance of the Old-Old Elderly,” Journal of Physical Therapy Science 26, no. 11 (November 2014): 1771–74.
27. 27. Tony Rosen, Karin A. Mack, and Rita K. Noonan, “Slipping and Tripping: Fall Injuries in Adults Associated with Rugs and Carpets,” Journal of Injury and Violence Research 5, no. 1 (January 2013): 61–69.

Chapter Five: People Matter Most

1. 1. Vivek Murthy, “Work and the Loneliness Epidemic,” Harvard Business Review, September 2017, https://hbr.org/cover-story/2017/09/work-and-the-loneliness-epidemic.
2. 2. Yuval N. Harari, Sapiens: A Brief History of Humankind (New York: Harper, 2015), 21.
3. 3. All data points in this paragraph taken from Michael Gerson, “Myths, Meaning, and Homo Sapiens,” Washington Post, June 11, 2015, https://www.washingtonpost.com/opinions/myths-meaning-and-homo-sapiens/2015/06/11/28660902-106f-11e5-a0dc-2b6f404ff5cf_story.html?utm_term=.6b56a3e5ce0b.
4. 4. Jared Diamond, Collapse: How Societies Choose to Fail or Succeed (New York: Viking, 2005).
5. 5. See, for example, the following: Johann Hari, Lost Connections: Uncovering the Real Causes of Depression—and the Unexpected Solutions (New York: Bloomsbury, 2018); Susan Pinker, The Village Effect: How Face-to-Face Contact Can Make Us Healthier and Happier (Toronto: Vintage Canada, 2015).
6. 6. See, for example, Dean Falk’s “Prelinguistic Evolution in Early Hominins: Whence Motherese?” and the various responses to this piece contained in Behavioral and Brain Sciences 27 (2004): 491–541.
7. 7. Sherry Turkle, Reclaiming Conversation: The Power of Talk in a Digital Age (New York: Penguin Press, 2015), 9.
8. 8. Michaeleen Doucleff, “Are Hunter-Gatherers the Happiest Humans to Inhabit Earth?” NPR (October 1, 2017), https://www.npr.org/sections/goatsandsoda/2017/10/01/551018759/are-hunter-gatherers-the-happiest-humans-to-inhabit-earth; University of Cambridge, “Farmers Have Less Leisure Time Than Hunter-Gatherers,” ScienceDaily (May 21, 2019), www.sciencedaily.com/releases/2019/05/190520115646.htm.
9. 9. See, for example, Brandon H. Hidaka, “Depression as a Disease of Modernity: Explanations for Increasing Prevalence,” Journal of Affective Disorders 140, no. 3 (November 2012): 205–14.
10. 10. Steven Pinker, The Better Angels of Our Nature: Why Violence Has Declined (New York: Penguin, 2012).
11. 11. For more on this general topic, see Antonia Ypsilanti et al.’s 2018 research: Susan Krauss Whitbourne, “5 Ways to Keep Loneliness From Turning into Depression,” Psychology Today, November 10, 2018, https://www.psychologytoday.com/intl/blog/fulfillment-any-age/201811/5-ways-keep-loneliness-turning-depression.
12. 12. For a more granular perspective on the rise of urbanization see Hannah Ritchie and Max Roser, “Urbanization,” Our World in Data (September 2018), https://ourworldindata.org/urbanization.
13. 13. R. I. M. Dunbar, “Neocortex Size as a Constraint on Group Size in Primates,” Journal of Human Evolution 22, no. 6 (June 1992): 469–93, https://doi.org/10.1016/0047-2484(92)90081-J.
14. 14. Aleks Krotoski, “Robin Dunbar: We Can Only Ever Have 150 Friends at Most …” Guardian, March 13, 2010, https://www.theguardian.com/technology/2010/mar/14/my-bright-idea-robin-dunbar.
15. 15. Susan Tardanico, “Is Social Media Sabotaging Real Communication?” Forbes, April 30, 2012, https://www.forbes.com/sites/susantardanico/2012/04/30/is-social-media-sabotaging-real-communication/#21a6352b2b62.
16. 16. Scott Barry Kaufman, “What Does It Mean to Be Self-Actualized in the 21st Century?” Scientific American, November 7, 2018, https://blogs.scientificamerican.com/beautiful-minds/what-does-it-mean-to-be-self-actualized-in-the-21st-century/; ——, “Who Created Maslow’s Iconic Pyramid?” Scientific American, April 23, 2019, https://blogs.scientificamerican.com/beautiful-minds/who-created-maslows-iconic-pyramid/.
17. 17. Barbara L. Fredrickson et al., “A Functional Genomic Perspective on Human Well-Being,” Proceedings of the National Academy of Sciences (July 2013), doi: 10.1073/pnas.1305419110; Antonella Delle Fave et al., “The Eudaimonic and Hedonic Components of Happiness: Qualitative and Quantitative Findings,” Social Indicators Research 100, no. 2 (January 2011): 185–207.
18. 18. J. B. Grubbs and J. J. Exline, “Trait Entitlement: A Cognitive-Personality Source of Vulnerability to Psychological Distress,” Psychological Bulletin 142, no. 11 (November 2016): 1204–26.
19. 19. Toshimasa Sone et al., “Sense of Life Worth Living (Ikigai) and Mortality in Japan: Ohsaki Study,” Psychosomatic Medicine 70, no. 6 (July 2008): 709, doi: 10.1097/PSY.0b013e31817e7e64.
20. 20. Brené Brown, The Gifts of Imperfection: Let Go of Who You Think You’re Supposed to Be and Embrace Who You Are (Center City, Minnesota: Hazelden Publishing, 2010), 6.

Chapter Six: Anchors

1. 1. For this description and the following paraphrases and quotations I rely on Baya Voce, “The Simple Cure for Loneliness,” YouTube video, TEDxSaltLakeCity, 13.27, posted October 7, 2016, https://www.youtube.com/watch?v=KSXh1YfNyVA.
2. 2. R. Christ Fraley, “Adult Attachment Theory and Research,” Department of Psychology University of Illinois at Urbana-Champaign, accessed September 17, 2019, http://labs.psychology.illinois.edu/~rcfraley/attachment.htm.
3. 3. As Harry Harlow underscored in his classical work on material bonding and separation: “Harlow’s Classic Studies Revealed the Importance of Maternal Contact,” Association for Psychological Science, accessed September 17, 2019, https://www.psychologicalscience.org/publications/observer/obsonline/harlows-classic-studies-revealed-the-importance-of-maternal-contact.html. See also Sarah Gibbens, “Is Maternal Instinct Only for Moms? Here’s the Science,” National Geographic, May 9, 2018, https://www.nationalgeographic.com/news/2018/05/mothers-day-2018-maternal-instinct-oxytocin-babies-science/, for new research on the importance of oxytocin release among different types of caregivers.
4. 4. Thomas Groennebaek and Kristian Vissing, “Impact of Resistance Training on Skeletal Muscle Mitochondrial Biogenesis, Content, and Function,” Frontiers in Physiology (September 15, 2017 online publication), doi: 10.3389/fphys.2017.00713.
5. 5. Perhaps no single figure did more to promote and celebrate the selfish theory as Ayn Rand: Eric Michael Johnson, “Ayn Rand vs. the Pygmies,” Slate, October 3, 2012, https://slate.com/technology/2012/10/groups-and-gossip-drove-the-evolution-of-human-nature.html.

Chapter Seven: Pivot to Heal: Fall and Therapeutic Winter

1. 1. Denise Mann, “Alcohol and a Good Night’s Sleep Don’t Mix,” WebMD (January 22, 2013), https://www.webmd.com/sleep-disorders/news/20130118/alcohol-sleep#1.
2. 2. The following are a great place to start: Bessel A. van der Kolk, The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma (New York: Penguin, 2015) and Gabor Maté, In the Realm of Hungry Ghosts: Close Encounters With Addiction (London: Vermilion, 2018).

Chapter Eight: Your Life Beyond

1. 1. Linda Carroll, Love Cycles: The Five Essential Stages of Lasting Love (California: New World Library, 2014).
2. 2. Esther Perel, Mating in Captivity (HarperCollins e-Books, 2014).
3. 3. V. Volynets et al., “Intestinal Barrier Function and the Gut Microbiome Are Differentially Affected in Mice Fed a Western-Style Diet or Drinking Water Supplemented with Fructose,” Journal of Nutrition 147, no. 5 (May 2017), doi: 10.3945/jn.116.242859.
4. 4. Keely A. Muscatell et al., “Exposure to an Inflammatory Challenge Enhances Neural Sensitivity to Negative and Positive Social Feedback,” Brain, Behavior, and Immunity 57 (October 2016), doi: 10.1016/j.bbi.2016.03.022.
5. 5. Philip Hunter, “The Inflammation Theory of Disease,” EMBO Reports 13, no. 11 (November 2012): 968–70.