Recent research has called into question the health benefits of regularly running for long periods of time, such as what’s done by ultra-marathoners and serial marathon runners, and a San Francisco Chronicle story takes a closer look at the evidence.

In the piece, writer Erin Allday highlights two studies released earlier this year suggesting potential negative health effects from long-distance running, as well as research presented last month showing fewer deaths among runners who log 20 miles per week at a leisure pace compared to lose who run longer and faster. Allday writes:

[The most recent study] and others all build evidence for the U-shaped curve of exercise benefits: that greater effort begets greater benefits, but only to a certain point. Then the benefits drop off, suggesting that there’s probably a maximum amount of exercise before it starts to become unhealthy.

In another way to look at the U-curve, someone running 10 miles a week may actually be healthier than someone running 60 miles a week – and an athlete doing the 5K fun-run associated with the San Francisco Marathon may be better off, health-wise, than… the handful of other runners attempting the 52.4-mile double marathon.

While the U-curve is pretty widely accepted, there’s disagreement over how much exercise may be too much. Many scientists say, assuming there exists a maximum safe amount of running, it’s probably so high that very few runners will ever get there.

Previously: Untrained marathoners may risk temporary heart damage
Photo by Jon Roig

This summer the U.S. Olympic team will for the first time use electronic health records, replacing the enormous piles of paper that were previously used to document the athletes’ medical care. Time reports:

With the electronic records, anyone caring for an Olympic athlete, from a trainer to a physical therapist to a physician treating an emergency injury, can get a quick look at the athlete’s medical history at a glance, and update it with the latest developments. “Every single encounter with a health care provider — whether it’s to provide an ice pack or a massage, chiropractic care or have their ankle taped — all of that should be recorded,” says Moreau. Each athlete decides what information goes into his file, and is assigned a point-of-care ombudsman, who coordinates the incoming data. Every piece of new information that the athlete adds to the record, such as an X-ray or an MRI or a blood test or physical, is sent to the coordinating physician. With the average Olympian seeing eight different doctors at any one time, that’s a huge time saver.

Previously: Olympic health concerns – for the spectators, Researchers challenge proposed testosterone testing in select female Olympic athletes and VA patients show “overwhelming interest” in sharing electronic health records with others

In sports, tearing the anterior cruciate ligament (ACL) is a serious injury that can leave athletes sidelined for six months or longer. As it turns out, men may be more prone to tearing their ACL than women, according to a new report published in The American Journal of Sports Medicine. A recent Reuters story examines the findings by Swedish researchers:

Overall, 56,659 people in Sweden tore a knee ligament during the study period. The researchers say that works out to an average of 78 tears for every 100,000 Swedish citizens.

Men accounted for about 34,000 of those tears, or 60 percent. Men also had 59 percent of the reconstructive surgeries associated with knee ligament injuries.

Swedish women tended to experience ACL injuries at a younger age (between ages 11 and 20, versus 21-30 for men).

When Nordenvall and his colleagues looked just at the age groups with the highest injury rates, men still had far more knee troubles. The numbers worked out to about 144 tears per 100,000 women between 11 and 20 years old, and 225 tears per 100,000 men aged 21-30.

Interestingly enough, this report contradicts an earlier study that found that women, not men, are more susceptible to tearing their ACL. Richard Nordenvall, MD, lead researcher of the new study, responds:

I think the difference is that earlier studies studied at-risk populations. In those studies, women are more prone to get injured. The difference with this study is that we studied the general population.

Previously: Contact sports OK for kids with one kidney, new study says and Researchers call for improvements to health screenings for female college athletes

If you’ve begun stoking Olympic fever by watching trials for U.S. athletes, it may be of interest to know some of the ways London officials have been readying the stage for the games, which open in three weeks.

In a Spoonful of Medicine Q&A posted today, Brian McCloskey, MD, lead health director for the Olympics, discusses infectious disease control, biomedical tools for gathering data and health surveillance systems in place for this summer’s festivities.

On the topic of tracking infectious diseases, McClosky says:

We will monitor all infectious diseases, but the main ones that will likely be an issue for us will be gastrointestinal diseases such as food poisoning and infectious diseases such as measles. There have been measles outbreaks in Europe and in UK in the past couple of years and those haven’t gone away.

Previously: Is the International Olympic Committee’s policy governing sex verification fair? and Continuing pollution restrictions used during Beijing Olympics could reduce cancer rates
Photo by rileyroxx

Updated 06-25-12: The International Olympic Committee has adopted the gender-policing policies discussed here last week. In a statement sent to reporters yesterday, Karkazis repeated her assertion that the policies are “unfair, unscientific and possibly discriminatory against women who may not meet traditional notions of femininity.”

***

06-18-12: In an article published in the New York Times today, Stanford bioethicist Katrina Karkazis, PhD, and Barnard College researcher Rebecca Jordan-Young, PhD, argue that the International Olympic Committee’s proposed new policy governing sex verification is neither fair nor rationale, and they offer recommendations for retooling the eligibility guidelines for Olympic female athletes. From the piece:

Testosterone is one of the most slippery markers that sports authorities have come up with yet. Yes, average testosterone levels are markedly different for men and women. But levels vary widely depending on time of day, time of life, social status and — crucially — one’s history of athletic training. Moreover, cellular responses range so widely that testosterone level alone is meaningless.

Testosterone is not the master molecule of athleticism. One glaring clue is that women whose tissues do not respond to testosterone at all are actually overrepresented among elite athletes.

As counterintuitive as it might seem, there is no evidence that successful athletes have higher testosterone levels than less successful ones.

…

Sex segregation is probably a good idea in some sports, at some levels and at some moments. But it is time to refocus policy discussions at every level so that sex segregation is one means to achieve fairness, not the ultimate goal. Ensuring gender equity through access to opportunity is just as important.

Unlike in doping cases, women with hyperandrogenism have not cheated. There is no reason to disqualify women whose bodies produce any of the complex ingredients that add up to athleticism, be they superb vision, big lungs, flexibility, long legs or testosterone.

Karkazis also discussed the issue of sex testing for elite female athletes in a recent 1:2:1 podcast.

Previously: Researchers challenge proposed testosterone testing in select female Olympic athletes and Gender ambiguity gets attention
Photo by Paul Foot

In a critique published online today in The American Journal of Bioethics, a Stanford bioethicist and colleagues warn that proposed policies by the International Olympic Committee and the International Association of Athletics Federations for testing the testosterone levels of select female athletes are unfair and may result in female athletes undergoing unnecessary, and potentially harmful, treatments to continue competing.

The testing policies adopted last year call for using testosterone levels to decide whether an athlete is “feminine” enough to compete as a woman. But as Katrina Karkazis, PhD, a medical anthropologist and senior research scholar at Stanford’s Center for Biomedical Ethics, and others explain in the paper, (subscription required) this approach could discriminate against women who may not meet traditional notions of femininity and distort the scientific evidence on the relationship between testosterone, sex and athletic performance. My colleague Tracie White reports:

 Although it is widely believed that chromosomal testing or genital exams can indicate definitively a person’s sex, such methods are flawed. Contrary to the general understanding that women have two X chromosomes and men have an X and a Y, there are actually too many variations on chromosomal markers to use the test accurately in all cases. While it is uncommon for women to have a Y chromosome, it does occur in a small number of women.

What’s more, regardless of chromosomes, female anatomy and physiology vary in ways that may make it difficult to quickly classify a person as male or female. There are individuals with intersex traits who are born with reproductive or sexual anatomy that doesn’t fit the typical definitions of female or male.

….

Of particular concern with the potential policies is the possible coercion of athletes into undergoing unnecessary and potentially harmful medical treatment if they are found to have hyperandrogenism. “If the athlete does not pass, she is banned from competition until she lowers her testosterone levels,” the authors write, noting that the treatment options would entail either pharmaceutical intervention or gonadectomy, both of which carry serious potential side effects.

Rather than adopting such policies, the authors recommend against gender policing by international sporting authorities. Karkazis recently discussed the issue of sex testing for elite female athletes in a recent 1:2:1 podcast.

Previously: Gender ambiguity gets attention
Photo by Bryan Allison

Findings recently published in the Clinical Journal of Sports Medicine suggest that current evaluation methods used in health screenings for female college athletes are lacking and could be putting students at risk for lifelong health problems.

In the study (subscription required), researchers collected data by survey from 257 NCAA Division I universities about when and how often athletes completed health histories and physical examinations. They also analyzed the content of pre-participation examination forms used to further assess players’ health. Medical News Today reports:

Of particular interest to the research team was whether the exams and forms comprehensively screen for the female athlete triad. The triad is an interrelationship between energy availability, menstrual function, and bone mineral density; researchers have found that in many sports, women do not take in enough nutrition (some have eating disorders), which leads to amenorrhea (absence of menstrual periods), and loss of bone density and strength.

The researchers found that 63 percent of the university athletic programs surveyed only completed a full history and exam on freshmen and transfer athletes, rather than every year or every other year.

Furthermore, only 25 universities (9 percent) had 9 or more of the 12 Female Athlete Triad Coalition screening recommendations included on their pre-participation examination forms.

Study results, researchers say, point to a need to revise the health evaluation process to include screening tools for the female athlete triad. Such tools could include having athletes complete 72-hour food diaries to measure energy intake and using accelerometers to measure energy expenditure, suggests Anne Hoch, DO, the study’s corresponding author. However, future studies are needed to determine which tools effectively screen for the female athlete triad.

Previously: Stanford physician discusses prevalence of overuse injuries among college athletes
Photo by mattradickal

There are three reasons why I love this time of year: the French Open wraps up on Sunday, followed by Wimbledon at the end of June and the U.S. Open at the end of August. Boring? Hardly! Thrilling? Frequently. The agility and strength of the athletes is jaw dropping as they slam the ball back and forth with precision and power, and sweat and grunts, delivering shots that make me marvel over and over again.

The current Grand Slam action definitely puts me in a tennis state of mind, so I was very interested in an article in the New York Times about a way to play tennis that had never occurred to me: blind tennis. Fortunately, it’s occurred to people who are blind or who have limited vision – and it’s growing in popularity.

Thomas Lin writes:

Blind tennis is made possible, scientists say, by the adaptability of the human brain – which appears to repurpose its visual area, the occipital cortex, to process sound and touch in response to blindness.

A series of studies discovered activity in the visual cortex when blind test subjects read Braille, and found that a blind woman could no longer make sense of the raised dots after suffering an occipital stroke. Another study, of sighted subjects who were blindfolded, showed that the occipital cortex began processing tactile and auditory information within five days.

If you missed the story or you haven’t checked it out, I highly recommend doing so – and the story has a nice video that’s worth watching.

Previous studies have shown that sports-related concussions may be caused by series of hits to the head over time rather than a single blow. Now new research suggests that sustaining repetitive hits may not affect all athletes in the same manner and that a select number could experience diminished cognitive function after a single season.

In the study (subscription required), researchers examined cognitive effects of repetitive head impacts over a single season among college football and hockey players. CNN’s The Chart blog reports:

In a study of college football players at three Division I universities, [researchers] found that subconcussive hits were not causing the dramatic lapses in cognition that might be considered a precursor to [chronic traumatic encephalopathy]. But when they re-examined the data, they found something slightly alarming.

A significant subgroup of the contact sport athletes – 22% – performed worse than expected on tests of verbal learning, compared with only about 4% of the non-contact sport athletes.

The data were gathered by nestling sensors in the helmets of 214 varsity football and hockey players and recording subconcussive hits during one full season. The sensors measured things like the force, location and rotation caused by hits to the head.

The contact sport athletes were compared to a control group of 45 athletes participating in non-contact sports like track, crew and Nordic skiing. Each group took cognitive tests before and shortly after the season.

According to the study, published in the journal Neurology, by the end of the season some contact sport players came up short on those tests.

As discussed here previously, research is underway here at Stanford to measure the number, force and direction of head impacts during games and practices for football players and athletes in other contact sports. In the intial study, researchers equipped Stanford football players with high-tech mouthpieces to determine what types of collisions cause concussions and whether there are any positions or plays associated with a greater risk of traumatic brain injuries. They intend to expand the study to the women’s field hockey and lacrosse teams.

Previously: High-tech mouthpieces used to advance medical understanding of concussions in football, Researchers develop new test for diagnosing concussions on the sidelines and When can athletes return to play? Stanford researchers provide guidance
Photo by GCSC

Much has been written about measures being taken to prevent and better diagnose concussions among athletes. Now findings published in the latest issue of American Journal of Sports Medicine show that age and gender may be important factors in how players recover from head injuries.

In the two-year study (subscription required), researchers monitored nearly 300 athletes from multiple states who had suffered a concussion. All of the participants completed a baseline test before taking three different post-concussion tests, the same ones used in professional sports following a head injury. According to a university release:

The study… found females performed worse than males on visual memory tests and reported more symptoms postconcussion.

Additionally, high school athletes performed worse than college athletes on verbal and visual memory tests, and some of the younger athletes still were impaired up to two weeks after their injuries.

“While previous research suggests younger athletes and females may take longer to recover from a concussion, little was known about the interactive effects of age and sex on symptoms, cognitive testing and postural stability,” said [Michigan State University researcher Tracey Covassin, PhD, who led the study.]

“This study confirms that age and sex have an impact on recovery, and future research should focus on developing treatments tailored to those differences.”

Previously: Report finds brain injuries rising among high school football players, Study suggests teens are more vulnerable to effects of sport-related concussions, Should parents worry about their kids playing football? and A conversation with Daniel Garza about football and concussions
Photo by Big West Conference