The Science of Yoga: The Risks and the Rewards (45 page)

86
vessels in the brain to contract:
Ronald Ley, “Breathing and the Psychology of Emotion, Cognition, and Behavior,” in Beverly H. Timmons and Ronald Ley, eds.,
Behavioral and Psychological Approaches to Breathing Disorders
(New York: Kluwer, 1994), pp. 86–88; L. C. Lum, “Hyperventilation Syndromes,” in Timmons and Ley,
Behavioral
, pp. 119–20.

86
cuts levels roughly in half:
Ibid., p. 119; for an early study, see Seymour S. Kety and Carl F. Schmidt, “The Effects of Active and Passive Hyperventilation on Cerebral Blood Flow, Cerebral Oxygen Consumption, Cardiac Output, and Blood Pressure of Normal Young Men,”
Journal of Clinical Investigation
, vol. 25 (1946), pp. 107–19.

87
three scientists in Sweden:
C. Frostell, J. N. Pande, and G. Hedenstierna, “Effects of high-frequency breathing on pulmonary ventilation and gas exchange,”
Journal of Applied Physiology
, vol. 55, no. 6 (1983), pp. 1854–61.

88
a standard figure:
Porth,
Essentials
, p. 515.

88
brain now gets more oxygen:
Ibid., p. 147.

88
increases in calm alertness:
Richard P. Brown and Patricia L. Gerbarg, “Sudarshan Kriya Yogic Breathing in the Treatment of Stress, Anxiety, and Depression: Part I—Neurophysiologic Model,”
Journal of Alternative and Complementary Medicine
, vol. 11, no. 1 (2005), pp. 189–201.

88
linked slow breathing to heightened vigilance:
Dirk S. Fokkema, “The Psychobiology of Strained Breathing and Its Cardiovascular Implications: A Functional System Review,”
Psychophysiology
, vol. 36, no. 2 (March 1999), pp. 164–75.

88
a study of nearly two dozen adults:
Luciano Bernardi, Peter Sleight, Gabriele Bandinelli, et al., “Effect of Rosary Prayer and Yoga Mantras on Autonomic Cardiovascular Rhythms: A Comparative Study,”
British Medical Journal
, vol. 323 (2001), pp. 1446–49.

88
“You’re not used”:
Choudhury,
Bikram Yoga
, p. 101.

88
Kundalini Yoga
: Khalsa,
Kundalini Yoga
, p. 25.

88
“one of the best things”:
Budilovsky and Adamson,
The Complete Idiot’s Guide
, p. 302.

89
“for anyone in need”:
Anonymous, “Yoga Instructional Book ‘Oxygen Yoga: A Spa Universe’ Now Available,” WiredPRNews.com, August 15, 2011.

89
wrote extensively:
Her writings were often in French. For an English work, see Thérèse Brosse, “A Psycho-physiological Study,”
Main Currents in Modern Thought
, no. 4 (July 1946), pp. 77–84.

89
“an extreme slowing”:
B. K. Bagchi and M. A. Wenger, “Electro-physiological Correlates of Some Yogi Exercises,”
EEG and Clinical Neurophysiology
, 1957, supplement 7, p. 146.

90
a gap of up to eleven degrees:
Elmer and Alyce Green,
Beyond Biofeedback
(New York: Delacorte Press, 1977), pp. 197–205.

90
biologists called it “sympathetic”:
Stanley Finger,
Origins of Neuroscience:
A History of Explorations into Brain Function
(New York: Oxford University Press, 2001), pp. 280–84.

91
“My name is Mel”:
Yoga class with Mel Robin, Yoga Loft, Bethlehem, Pennsylvania, April 14, 2007.

93
cast the topic:
Yoga class with Mel Robin, Yoga Loft, Bethlehem, Pennsylvania, July 24, 2007.

94
a place in his book:
Robin,
A Physiological Handbook
, pp. 137–40.

94
had us turn to another page:
Ibid., p. 147.

95
The Relaxation Response
: Herbert Benson and Miriam Z. Klipper,
The Relaxation Response
(New York: HarperCollins, 2000).

96
average of 13 percent:
Chaya et al., “The Effect of Long Term Combined Yoga Practice.” See also M. S. Chaya and H. R. Nagendra, “Long-term effect of yogic practices on diurnal metabolic rates of healthy subjects,”
International Journal of Yoga
, vol. 1, no. 1 (January–June 2008), pp. 27–32.

97
New York Times
profiled:
Lizette Alvarez, “Rebel Yoga,”
New York Times
, January 23, 2011, Section WE, p. 1.

97
“rev up your metabolism”:
Tara Stiles,
Slim Calm Sexy Yoga
(New York: Rodale, 2010), p. 150.

98
“Yoga affects the mind”:
Interview, Mayasandra S. Chaya, Swami Vivekananda Yoga Research Foundation, Bangalore, India, June 13, 2011.

98
nearly one million despairing people:
Anonymous, “Depression,” World Health Organization.

99
known about GABA since the 1950s:
Max R. Bennett,
History of the Synapse
(Amsterdam: Harwood Academic Publishers, 2001), pp. 83–85.

100
published in 2007:
Chris C. Streeter, J. Eric Jensen, Ruth M. Perlmutter, et al., “Yoga Asana Sessions Increase Brain GABA Levels: A Pilot Study,”
Journal of Alternative and Complementary Medicine
, vol. 13, no. 4 (2007), pp. 419–26.

100
“clear public health advantages”:
Quoted in Gina
M. Digravio, “Study Finds Yoga Associated with Elevated Brain GABA Levels,” Boston University news release, May 22, 2007.

100
published in 2010:
Chris C. Streeter, Theodore H. Whitfield, Liz Owen, et al., “Effects of Yoga Versus Walking on Mood, Anxiety, and Brain GABA Levels: A Randomized Controlled MRS Study,”
Journal of Alternative and Complementary Medicine
, vol. 16, no. 11 (2010), pp. 1145–52.

101
her website advised:
Liz Owen Yoga,
www.lizowenyoga.com.

101
reported in their 2006 paper:
Sat Bir S. Khalsa and Stephen Cope, “Effects of a Yoga Lifestyle Intervention on Performance-Related Characteristics of Musicians: A Preliminary Study,”
Medical Science Monitor
, vol. 12, no. 8 (August 2006), pp. CR325–CR331.

102
Khalsa and colleagues reported:
Sat Bir S. Khalsa, Stephanie M. Shorter, Stephen Cope, et al., “Yoga Ameliorates Performance Anxiety and Mood Disturbance in Young Professional Musicians,”
Applied Psychophysiology and Biofeedback
, vol. 34, no. 4 (December 2009), pp. 279–89.

IV: Risk of Injury

103
“Real yoga is as safe”:
Swami Gitananda Giri, “Real Yoga Is as Safe as Mother’s Milk,”
Yoga Life
, vol. 28, no. 12 (December 1997), pp. 3–12.

104
challenged the reports as biased:
See, for instance, Enoch Haga, “Yoga,”
Journal of the American Medical Association
, vol. 218, no. 1 (October 4, 1971), p. 98.

104
feature lengthy addendums:
Robin,
A Physiological Handbook
, pp. 511–18; Robin,
A Handbook
, pp. 833–41.

106
“I make it as hard as possible”:
Yoga class with Glenn Black, Sankalpah Yoga, New York City, January 24, 2009.

110
reports began to emerge:
One of the earliest, if not the first, is Gilbert E. Corrigan, “Fatal Air Embolism after Yoga Breathing Exercises,”
Journal of the American Medical Association
, vol. 210, no. 10 (December 8, 1969), p. 1923.

110
an examination showed:
Joseph Chusid, “Yoga Foot Drop,”
Journal of the American Medical Association
, vol. 217, no. 6 (August 9, 1971), pp. 827–28.

110
in Vajrasana had clamped:
Robin,
A Physiological Handbook
, p. 513.

111
chanting while standing:
Anonymous, “The Yoga Ailment,”
Time
, August 23, 1971, p. 52.

111
similar cases emerged:
See, for instance, Caryn M. Vogel, Roger Albin, and James W. Albers, “Lotus Footdrop: Sciatic Neuropathy in the Thigh,”
Neurology
, vol. 41, no. 4 (April 1991), pp. 605–6; Thomas G. Mattio, Takashi Nishida, and Michael M. Minieka, “Lotus Neuropathy: Report of a Case,”
Neurology
, vol. 42 (August 1992), p. 1636.

111
One of the worst:
Melanie Walker, Gregg Meekins, and Shu-Ching Hu, “Yoga Neuropathy: A Snoozer,”
Neurologist
, vol. 11, no. 3 (May 2005), pp. 176–78.

112
published his pioneering research:
See, for example, D. Denny-Brown and W. Ritchie Russell, “Experimental Cerebral Concussion,”
Brain
, vol. 64 (1941), pp. 93–164.

112
His new warning:
W. Ritchie Russell, “Yoga and the Vertebral Arteries,”
British Medical Journal
, vol. 1, no. 5801 (March 11, 1972), p. 685.

113
typically move the vertebrae:
Robin,
A Physiological Handbook
, pp. 72–75. Extreme movements of the neck can, short of strokes, also disrupt the flow of blood to the brain, causing dizziness and nystagmus, an involuntary jerking of the eye. See Judith Hanson Lasater,
Yogabody: Anatomy, Kinesiology, and Asana
(Berkeley: Rodmell Press, 2009), pp. 51–52.

114
describe the final journey:
Francesco Cacciola, Umesh Phalke, and Atul Goel, “Vertebral Artery in Relationship to C1-C2 Vertebrae: An Anatomical Study,”
Neurology India
, vol. 52, no. 2 (June 2004), pp. 178–84.

114
feeds such structures:
Adel K. Afifi and Ronald A. Bergman,
Functional Neuroanatomy: Text and Atlas
, 2nd ed. (New York: Lange Medical Books, 2005), pp. 352–54.

114
recover most functions:
Abdullah Bin Saeed, Ashfaq Shuaib, Ghanem Al-Sulaiti, et al., “Vertebral Artery Dissection: Warning Symptoms, Clinical Features and Prognosis in 26 Patients,”
Canadian Journal of Neurological Sciences
, vol. 27, no. 4 (November 2000), pp. 292–96; Wouter I. Schievink, “Spontaneous Dissection of the Carotid and Vertebral Arteries,”
New England Journal of Medicine
, vol. 344, no. 12 (March 22, 2001), pp. 898–906.

114
a prominent type:
Elisabeth Rosenthal, “Rare Threat of Stroke at the Beauty Salon,”
New York Times
, April 28, 1993, Section C, p. 11.

115
“as far back as possible”:
Iyengar,
Light on Yoga
, pp. 107–109.

116
“The body should be”:
Ibid., p. 211.

116
a gruesome case study:
Willibald Nagler, “Vertebral Artery Obstruction by Hyperextension of the Neck: Report of Three Cases,”
Archives of Physical Medicine and Rehabilitation
, vol. 54, no. 5 (May 1973), pp. 237–40; W. Nagler, “Mechanical Obstruction of Vertebral Arteries During Hyperextension of Neck,”
British Journal of Sports Medicine
, vol. 7, nos. 1–2 (1973), pp. 92–97.