The brain’s reward system . . . can become highly connected: Li Wang et al., “Altered Default Mode and Sensorimotor Network Connectivity with Striatal Subregions in Primary Insomnia: A Resting-State Multi-Band fMRI Study.” Frontiers in Neuroscience 12 (2018): 917; doi: 10.3389/fnins.2018.00917.
In brain-imaging studies, focused breathing, mindfulness, and repeating a mantra: Kathleen A. Garrison et al., “Meditation Leads to Reduced Default Mode Network Activity Beyond an Active Task.” Cognitive, Affective, & Behavioral Neuroscience 15, no. 3 (2015): 712–20; Judson A. Brewer et al., “Meditation Experience Is Associated with Differences in Default Mode Network Activity and Connectivity.” Proceedings of the National Academy of Sciences of the USA 108, no. 50 (2011): 20254–59; Rozalyn Simon et al., “Mantra Meditation Suppression of Default Mode Beyond an Active Task: A Pilot Study.” Journal of Cognitive Enhancement 1, no. 2 (2017): 219–27.
In one unusual case study: Yochai Ataria, Yair Dor-Ziderman, and Aviva Berkovich-Ohana, “How Does It Feel to Lack a Sense of Boundaries? A Case Study of a Long-Term Mindfulness Meditator.” Consciousness and Cognition 37 (2015): 133–47; Yair Dor-Ziderman et al., “Mindfulness-Induced Selflessness: A MEG Neurophenomenological Study.” Frontiers in Human Neuroscience 7 (2013): 582.
At least one study has tried to capture this effect: Gregory N. Bratman et al., “Nature Experience Reduces Rumination and Subgenual Prefrontal Cortex Activation.” Proceedings of the National Academy of Sciences of the USA 112, no. 28 (2015): 8567–72.
Individuals who suffer from depression show: J. Paul Hamilton et al., “Depressive Rumination, the Default-Mode Network, and the Dark Matter of Clinical Neuroscience.” Biological Psychiatry 78, no. 4 (2015): 224–30.
Magnetically stimulating the prefrontal cortex: Conor Liston et al., “Default Mode Network Mechanisms of Transcranial Magnetic Stimulation in Depression.” Biological Psychiatry 76, no. 7 (2014): 517–26.
Intravenous infusions of the drug ketamine: Milan Scheidegger et al., “Ketamine Decreases Resting State Functional Network Connectivity in Healthy Subjects: Implications for Antidepressant Drug Action.” PLOS ONE 7, no. 9 (2012): e44799.
This may explain why the psychological benefits: Femke Beute and Yvonne A. W. de Kort, “The Natural Context of Wellbeing: Ecological Momentary Assessment of the Influence of Nature and Daylight on Affect and Stress for Individuals with Depression Levels Varying from None to Clinical.” Health & Place 49 (2018): 7–18.
“Diving into wild water is the great bringer-back of reality”: Andrew Fusek Peters, Dip: Wild Swims from the Borderlands (London: Rider, 2014). Quotes appear on pp. 143 and 212.
the default mode is relentlessly verbal: Elena Makovac et al., “The Verbal Nature of Worry in Generalized Anxiety: Insights from the Brain.” NeuroImage: Clinical 17 (2017): 882–92.
Mindfulness practices teach people: Norman A. S. Farb et al., “Attending to the Present: Mindfulness Meditation Reveals Distinct Neural Modes of Self-Reference.” Social Cognitive and Affective Neuroscience 2, no. 4 (2007): 313–22.
Among highly experienced meditators: Veronique A. Taylor et al. “Impact of Meditation Training on the Default Mode Network During a Restful State.” Social Cognitive and Affective Neuroscience 8, no. 1 (2013): 4–14; Richard Harrison et al., “Trait Mindfulness Is Associated with Lower Pain Reactivity and Connectivity of the Default Mode Network.” Journal of Pain (2018); https://doi.org/10.1016/j.jpain.2018.10.011.
two pressures shaped the development of the human brain: Alexandra G. Rosati, “Foraging Cognition: Reviving the Ecological Intelligence Hypothesis.” Trends in Cognitive Sciences 21, no. 9 (2017): 691–702.
Like green exercise, these drugs alter consciousness: Fernanda Palhano-Fontes et al., “The Psychedelic State Induced by Ayahuasca Modulates the Activity and Connectivity of the Default Mode Network.” PLOS ONE 10, no. 2 (2015): e0118143; Robin L. Carhart-Harris et al., “Neural Correlates of the Psychedelic State as Determined by fMRI Studies with Psilocybin.” Proceedings of the National Academy of Sciences of the USA 109, no. 6 (2012): 2138–43.
During an LSD trip: Enzo Tagliazucchi et al., “Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution.” Current Biology 26, no. 8 (2016): 1043–50.
intense spiritual experience while in nature: Terry Louise Terhaar, “Evolutionary Advantages of Intense Spiritual Experience in Nature.” Journal for the Study of Religion, Nature & Culture 3, no. 3 (2009): 303–39.
“I didn’t just feel amazing. I felt free”: Rich Roll, Finding Ultra: Rejecting Middle Age, Becoming One of the World’s Fittest Men, and Discovering Myself (New York: Crown/Three Rivers Press, 2012). Quote appears on p. 13.
“I felt a complete merging”: Woman’s hiking anecdote and quote appears in Laura M. Fredrickson and Dorothy H. Anderson, “A Qualitative Exploration of the Wilderness Experience as a Source of Spiritual Inspiration.” Journal of Environmental Psychology 19, no. 1 (1999): 21–39.
Analyses of journal entries: Kathryn E. Schertz et al., “A Thought in the Park: The Influence of Naturalness and Low-Level Visual Features on Expressed Thoughts.” Cognition 174 (2018): 82–93.
“Connecting with nature embeds us more deeply”: Holli-Anne Passmore and Andrew J. Howell, “Eco-Existential Positive Psychology: Experiences in Nature, Existential Anxieties, and Well-Being.” The Humanistic Psychologist 42, no. 4 (2014): 370–88.
walking in a nature reserve for fifteen minutes: F. Stephan Mayer et al., “Why Is Nature Beneficial? The Role of Connectedness to Nature.” Environment and Behavior 41, no. 5 (2009): 607–43.
In 2013, the city of Melbourne, Australia: You can explore the map of Melbourne’s trees and email a tree here: http://melbourneurbanforestvisual.com.au/#mapexplore.
The human longing to connect with nature: Stephen R. Kellert and Edward O. Wilson, eds., The Biophilia Hypothesis (Washington, DC: Island Press, 1993).
individuals who feel a stronger connection to nature: Colin A. Capaldi, Raelyne L. Dopko, and John M. Zelenski, “The Relationship Between Nature Connectedness and Happiness: A Meta-Analysis.” Frontiers in Psychology 5 (2014): doi: 10.3389/fpsyg.2014.00976; Anne Cleary et al., “Exploring Potential Mechanisms Involved in the Relationship Between Eudaimonic Wellbeing and Nature Connection.” Landscape and Urban Planning 158 (2017): 119–28.
People who make more frequent visits to natural spaces: M. P. White et al., “Natural Environments and Subjective Wellbeing: Different Types of Exposure Are Associated with Different Aspects of Wellbeing.” Health & Place 45 (2017): 77–84.
One study tracked the daily movements: George MacKerron and Susana Mourato, “Happiness Is Greater in Natural Environments.” Global Environmental Change 23, no. 5 (2013): 992–1000.
Americans spend 93 percent of their time indoors: Neil E. Klepeis et al., “The National Human Activity Pattern Survey (NHAPS): A Resource for Assessing Exposure to Environmental Pollutants.” Journal of Exposure Analysis and Environmental Epidemiology 11, no. 3 (2001): 231–52.
Many listen to recordings: I learned this fact from Scott Kelly, Endurance: My Year in Space, A Lifetime of Discovery (New York: Knopf, 2017).
On one expedition, American astronaut and flight engineer Don Pettit: Details about Pettit’s space station garden are drawn from multiple reports and previously published interviews, including his NASA chronicles and Letters from Space blog (https://blogs.nasa.gov/letters/author/dpettitblog/; and https://spaceflight.nasa.gov/station/crew/exp6/spacechronicles.html) as well as Debbora Battaglia, “Aeroponic Gardens and Their Magic: Plants/Persons/Ethics in Suspension.” History and Anthropology 28, no. 3 (2017): 263–92.
“When we relate to nature”: Rollo May, Man’s Search for Himself (New York: Norton, 2009). Quote appears on p. 49.
the old friends hypothesis: Christopher A. Lowry et al., “The Microbiota, Immunoregulation, and Mental Health: Implications for Public Health.” Curren
t Environmental Health Reports 3, no. 3 (2016): 270–86.
the lack of exposure to dirt in modern society: Graham A. W. Rook, Charles L. Raison, and Christopher A. Lowry, “Childhood Microbial Experience, Immunoregulation, Inflammation, and Adult Susceptibility to Psychosocial Stressors and Depression.” In Bernhard T. Baune, ed., Inflammation and Immunity in Depression: Basic Science and Clinical Applications (Cambridge, MA: Academic Press, 2018), 17–44; Charles L. Raison, Christopher A. Lowry, and Graham A. W. Rook, “Inflammation, Sanitation, and Consternation: Loss of Contact with Coevolved, Tolerogenic Microorganisms and the Pathophysiology and Treatment of Major Depression.” Archives of General Psychiatry 67, no. 12 (2010): 1211–24.
“You can just be yourself”: Quote from public tweet shared by the Conservation Volunteers Hollybush on October 15, 2018.
women with breast cancer reported . . . a “shoulder-to-shoulder support”: Aileen V. Ireland et al., “Walking Groups for Women with Breast Cancer: Mobilising Therapeutic Assemblages of Walk, Talk and Place.” Social Science & Medicine (2018): https://doi.org/10.1016/j.socscimed.2018.03.016.
A 2017 analysis of urban community gardens: Søren Christensen, “Seeding Social Capital? Urban Community Gardening and Social Capital.” Civil Engineering and Architecture 5, no. 3 (2017): 104–23.
“Whereas before it was just my home”: J. Mailhot, “Green Social Work and Community Gardens: A Case Study of the North Central Community Gardens.” Master’s thesis, University of Nordland, Bodo, Norway, 2015.
The Beach 91st Street Community Garden: Joana Chan, Bryce DuBois, and Keith G. Tidball, “Refuges of Local Resilience: Community Gardens in Post-Sandy New York City.” Urban Forestry & Urban Greening 14, no. 3 (2015): 625–35. Quote appears on p. 631.
“People must belong to a tribe”: E. O. Wilson, Consilience: The Unity of Knowledge (New York: Knopf, 1998). Quote appears on p. 6.
volunteers reported an increase in optimism: 2016 National Evaluation of Green Gym, supported by the New Economics Foundation (NEF). Full report available at https://www.tcv.org.uk/greengym/health-benefits/green-gym-research.
In 2017, researchers at the University of Westminster: This study has not yet been published in a scientific journal, but you can learn more about it at https://www.tcv.org.uk/greengym/trust-me-im-a-doctor/university-westminster-findings.
In cities as diverse as Delhi, London, and Milwaukee: Debarati Mukherjee et al., “Park Availability and Major Depression in Individuals with Chronic Conditions: Is There an Association in Urban India?” Health & Place 47 (2017): 54–62; Mathew P. White et al., “Would You Be Happier Living in a Greener Urban Area? A Fixed-Effects Analysis of Panel Data.” Psychological Science 24, no. 6 (2013): 920–28; Kirsten M. M. Beyer et al., “Exposure to Neighborhood Green Space and Mental Health: Evidence from the Survey of the Health of Wisconsin.” International Journal of Environmental Research and Public Health 11, no. 3 (2014): 3453–72.
When the Pennsylvania Horticultural Society: Eugenia C. South et al., “Effect of Greening Vacant Land on Mental Health of Community-Dwelling Adults: A Cluster Randomized Trial.” JAMA Network Open 1, no. 3 (2018): e180298.
“Root growth is essentially opportunistic”: Thomas O. Perry, “Tree Roots: Facts and Fallacies.” Arnoldia 49, no. 4 (1989): 3–24.
Chapter 7: How We Endure
In North America alone: Statistics about ultramarathon participation in North America are from http://realendurance.com/summary.php.
“reminds us that through adversity there is hope”: Comrades Marathon, “Beginnings”; http://www.comrades.com/marathoncentre/club-details/8-news/latest-news/326-history-of-comrades [inactive].
the word athlete derives from: Robin Harvie, The Lure of Long Distances: Why We Run (New York: Public Affairs, 2011). Quote appears on p. 140.
“the passage of time turned into a dragging”: David Heinz, Victor Vogel, et al., “Disturbed Experience of Time in Depression-Evidence from Content Analysis.” Frontiers in Human Neuroscience 12 (2018): 66.
runners reported “distortions in time”: Dolores A. Christensen, “Over the Mountains and Through the Woods: Psychological Processes of Ultramarathon Runners.” PhD dissertation, Springfield College, 2017.
Ultrarunner Robin Harvie remembers reaching: Harvie, The Lure of Long Distances. Quotes appear on pp. 239–40 and 67.
“You don’t have to get rid of the pain”: Jennifer Pharr Davis, The Pursuit of Endurance: Harnessing the Record-Breaking Power of Strength and Resilience (New York: Viking, 2018). Quote appears on p. 293.
Researcher Karen Weekes followed ten athletes: Karen Weekes, “Cognitive Coping Strategies and Motivational Profiles of Ultra-Endurance Athletes.” PhD dissertation, Dublin City University, 2004.
“a series of brutal, soul-crushing hills”: Torres shared this story in our conversation; some details and quotes also are drawn from her essay about the Kauai Marathon experience at https://christinatorres.org/2016/09/21/the-sweetness-of-surrender-kauai-marathon-2016/.
“being alive is more important than hands and feet”: “Yukon Arctic Ultra Racer May Lose Hands, Feet to Frostbite.” CBC News, February 14, 2018; http://www.cbc.ca/news/canada/north/yukon-arctic-ultra-zanda-pollhammer-1.4535514.
Kirsty-Ann Burroughs interviewed endurance runners: Kirsty-Ann Burroughs, “Faith and Endurance: The Relationship Between Distinct Theologies and the Experience of Running for Christian Women.” PhD dissertation, University of Brighton, 2004.
researchers analyzed the hormones: Robert H. Coker et al., “Metabolic Responses to the Yukon Arctic Ultra: Longest and Coldest in the World.” Medicine and Science in Sports and Exercise 49, no. 2 (2017): 357–62.
irisin also has powerful effects on the brain: Christiane D. Wrann et al., “Exercise Induces Hippocampal BDNF Through a PGC-1α/FNDC5 Pathway.” Cell Metabolism 18, no. 5 (2013): 649–59; David A. Raichlen and Gene E. Alexander, “Adaptive Capacity: An Evolutionary Neuroscience Model Linking Exercise, Cognition, and Brain Health.” Trends in Neurosciences 40, no. 7 (2017): 408–21; Ning Chen et al., “Irisin, an Exercise-Induced Myokine as a Metabolic Regulator: An Updated Narrative Review.” Diabetes/Metabolism Research and Reviews 32, no. 1 (2016): 51–59.
Lower levels are associated with an increased risk of depression: Wen-Jun Tu et al., “Decreased Level of Irisin, a Skeletal Muscle Cell-Derived Myokine, Is Associated with Post-Stroke Depression in the Ischemic Stroke Population.” Journal of Neuroinflammation 15, no. 1 (2018): 133; Csaba Papp et al., “Alteration of the Irisin-Brain-Derived Neurotrophic Factor Axis Contributes to Disturbance of Mood in COPD Patients.” International Journal of Chronic Obstructive Pulmonary Disease 12 (2017): 2023–33.
elevated levels can boost motivation: Judit Zsuga et al., “FNDC5/Irisin, a Molecular Target for Boosting Reward-Related Learning and Motivation.” Medical Hypotheses 90 (2016): 23–28.
Injecting the protein directly into the brains of mice: Aline Siteneski et al., “Central Irisin Administration Affords Antidepressant-Like Effect and Modulates Neuroplasticity-Related Genes in the Hippocampus and Prefrontal Cortex of Mice.” Progress in Neuro-Psychopharmacology and Biological Psychiatry 84 (2018): 294–303.
Higher blood levels of irisin: Muaz Belviranli et al., “The Relationship Between Brain-Derived Neurotrophic Factor, Irisin and Cognitive Skills of Endurance Athletes.” Physician and Sportsmedicine 44, no. 3 (2016): 290–96; Yunho Jin et al., “Molecular and Functional Interaction of the Myokine Irisin with Physical Exercise and Alzheimer’s Disease.” Molecules 23, no. 12 (2018): e3229; Dong-Jie Li et al., “The Novel Exercise-Induced Hormone Irisin Protects Against Neuronal Injury via Activation of the Akt and ERK½ Signaling Pathways and Contributes to the Neuroprotection of Physical Exercise in Cerebral Ischemia.” Metabolism 68 (2017): 31–42.
Irisin . . . is the best-known example of a myokine: Ning Chen et al., “Irisin, an Exercise-Induced Myokine as a Metabolic Regulator: An Updated Na
rrative Review.” Diabetes/Metabolism Research and Reviews 32, no. 1 (2016): 51–59.
One of the greatest recent scientific breakthroughs: For an introduction to the concept of myokines, see: Martin Whitham and Mark A. Febbraio, “The Ever-Expanding Myokinome: Discovery Challenges and Therapeutic Implications.” Nature Reviews Drug Discovery 15, no. 10 (2016): 719–29; Svenia Schnyder and Christoph Handschin, “Skeletal Muscle as an Endocrine Organ: PGC-1α, Myokines and Exercise.” Bone 80 (2015): 115–25; Jun Seok Son et al., “Exercise-Induced Myokines: A Brief Review of Controversial Issues of This Decade.” Expert Review of Endocrinology & Metabolism 13, no. 1 (2018): 51–58.
One of these proteins is irisin: Jill Fox et al., “Effect of an Acute Exercise Bout on Immediate Post-Exercise Irisin Concentration in Adults: A Meta-Analysis.” Scandinavian Journal of Medicine and Science in Sports 28, no. 1 (2018): 16–28.
Following a single treadmill workout: Stella S. Daskalopoulou et al., “Plasma Irisin Levels Progressively Increase in Response to Increasing Exercise Workloads in Young, Healthy, Active Subjects.” European Journal of Endocrinology 171, no. 3 (2014): 343–52.
A 2018 scientific paper identified thirty-five proteins: Martin Whitham et al., “Extracellular Vesicles Provide a Means for Tissue Crosstalk During Exercise.” Cell Metabolism 27, no. 1 (2018): 237–51.
Some myokines even metabolize a neurotoxic chemical: Leandro Z. Agudelo et al., “Skeletal Muscle PGC-1α1 Modulates Kynurenine Metabolism and Mediates Resilience to Stress-Induced Depression.” Cell 159, no. 1 (2014): 33–45; Maja Schlittler et al., “Endurance Exercise Increases Skeletal Muscle Kynurenine Aminotransferases and Plasma Kynurenic Acid in Humans.” American Journal of Physiology—Cell Physiology 310, no. 10 (2016): C836–40.
The Joy of Movement Page 24
