Men are famous for ignoring aches and pains. It's macho. Men get physical exams less often than women. They tend to remain silent if worried about their health. When hurt, their impulse is to shun doctors and rely on home remedies, like avoiding heavy lifting to ease backaches. Male athletes play through injuries. It's all about virility and manliness.
The stereotype has exceptions, of course. But denial of injury and ill health — from the relatively inconsequential to the grave — is common enough that physicians seek ways to encourage men to be more forthcoming.
So it pays to listen carefully when guys start talking about intolerable pain and upended lives. Doing so led me to an unexpected finding that I have confirmed in a trove of federal data. It suggests thatyoga can be remarkably dangerous — for men.
Guys who bend, stretch and contort their bodies are relatively few in number, perhaps one in five out of an estimated 20 million practitioners in the United States and 250 million around the globe. But proportionally, they are reporting damage more frequently than women, and their doctors are diagnosing more serious injuries — strokes and fractures, dead nerves and shattered backs. In comparison, women tell mainly of minor upsets.
Men who are breaking the code of silence are doing so with physicians in hospital emergency rooms, who in turn report their findings to the federal government.
Their outspokenness reveals much about modern yoga and suggests ways it can be made safer. As a practitioner since 1970, I know some of the guy hazards personally and have learned through painful experience how to live with my inflexible body.
The male disclosures help explain one of the central mysteries of modern yoga — why it is largely a feminine pursuit. As Yoga Journal, the field's top magazine, put the question: "Where Are All the Men?"
Science has long viewed the female body as relatively elastic. Now the new disclosures suggest that women who tie themselves in knots also enjoy a lower risk of damage. It seems like common sense.
Surprisingly, evidence of the male danger has, to my knowledge, never before been made public. Nor has its flip side — that women seem less vulnerable. The subject of male risk merits discussion if only because the booming yoga industry has long targeted men as a smart way to expand its franchise.
Informal observations hint at possible explanations. Yoga experts say women tend to see classes as refuges while men see challenges — their goal at times to impress the opposite sex.
Women say men push themselves too far, too fast. Men admit to liking the intensity but say the problem is pushy teachers who force them into advanced poses while urging them to ignore pain.
I stumbled on the issue after my book, published in February, laid out a century and a half of science and, in its chapter on injuries, contradicted the usual image of yoga as completely safe. The yoga establishment makes billions of dollars by selling itself as a path to healthy perfection. Predictably, it responded with sharp denials.
I also received a surprising number of moving replies from injured yogis — male and female — including stroke victims.
A letter initiated my inquiry. In April, a man told how an agonizing back injury had turned his life into "a living hell." Too many instructors, he wrote, are "pushing us too hard and having us do dangerous poses."
The "us" resonated.
Suddenly, I realized his cry sounded familiar.
I raced through a correspondence file and saw that many of the letters about serious damage had come from men.
Tara Stiles, a yoga teacher who runs a popular studio in Manhattan, told me that guys have more muscle (one reason for their relative inflexibility) and can thus force themselves into challenging poses they might otherwise find impossible. It seemed a plausible explanation for blinding pain.
Other teachers echoed her analysis and cited supporting anecdotes.
Yoga poses are unisex. But in my research, I found a world of poorly known information on gender disparity.
"Science of Flexibility," by Michael J. Alter, explained how the pelvic regions of women are shaped in a way that permits an unusually large range of motion and joint play. In yoga, the pelvis is the central pivot for extreme bending of the legs, spine and torso.
In June, I turned to the Consumer Product Safety Commission and its National Electronic Injury Surveillance System, which monitors hospital emergency rooms. In July, officials sent me 18 years of annual survey data that summarized the admission records for yoga practitioners hurt between 1994 and 2011, the maximum available span.
First, I needed a baseline that would let me compare the guy admissions to males doing yoga in the United States. Figures in the yoga literature described men as making up some 10 percent of practitioners at the beginning of the period and 23 percent at the end. So the middle ground seemed to be roughly 16 percent.
Then I dug into the medical data. The analysis took weeks, but the results spoke volumes.
If men were getting hurt in proportion to their numbers, the rate of injury would have been about 16 percent — my estimate for the fraction of practitioners who were male. But the rate was higher. Over all, I found that men accounted for slightly more than 24 percent of the admissions to hospital emergency rooms.
To deepen my analysis, I focused on specific injuries, especially ones inside the body. Guys, it turned out, accounted for 20 percent of the torn muscles and damaged ligaments, which result in swollen joints. Dislocations of the knee, shoulder and other joints came in at 24 percent.
The figure for broken bones and fractures was 30 percent. The injury sites ranged from the toe to the tibia, the bigger of the two bones in the lower leg.
For nerve damage, which can result in pain and lost muscle control, the male figure jumped to more than 70 percent. The cases included sciatica, where compression of a spinal nerve in the lower back can result in pains that race down the back, hip and leg.
I found the trend in women's admissions to be just the opposite. The major injuries were few proportionately, and the minor traumas quite abundant. Women, for instance, accounted for a vast majority of the fainting episodes.
None of this means that women go unharmed, as my letter files and the admission records show. But men seem to get it worse.
In August, I shared my analysis with Loren M. Fishman, a doctor in Manhattan who uses yoga in his rehabilitation practice and whom I profile in my book. "It's men's strength turning against them," he remarked.
Some yoga practitioners will surely see my analysis as unconvincing. That's O.K. It's the kind of topic that can only benefit from thorough discussion — as well as rigorous new studies that can rule out the possibility of false clues.
Skeptics may argue that the injured guys are simply wimps who are inflating the male-injury figures.
That seems unlikely. A new book, "Hell-Bent," by Benjamin Lorr, evokes the contrary ethos in its subtitle: "Obsession, Pain, and the Search for Something Like Transcendence in Competitive Yoga."
Happily, the field is evolving in ways that may enhance safety.
All-male classes, by definition, avoid the flexibility gap between women and men and instead play to masculine strengths. The classes tend to emphasize muscle building and fitness moves like squats, as well as poses. Their developers tend to avoid talk of injuries, a marketing no-no.
The styles include YoGuy ("be comfortable") and Broga (as in bro yoga, "where it's O.K. if you can't touch your toes"). A number of studios offer what they call yoga for dudes.
I'm a yoga enthusiast, not a basher. I do my routine every day and want the practice to thrive — but to do so honestly, with public candor about its real strengths and weaknesses.
From reader mail, I know that many yogis are working hard to make the practice safer. The male risk factor seems an important consideration in the redesign of poses and routines. And I'm sure instructors of mixed classes will find many ways of reducing any danger. A first step would be frank discussions with students.
In time, it seems likely that the myth of perfection will give way to the reality of better yoga — for everyone, including guys.