Biology: December 2008 Archives


December 25, 2008

One question a lot of athletes have is whether they can work out when they're sick. Obviously, you don't want to lose training time, but on the other hand you don't want to make yourself too sick by training when you should be resting. The conventional wisdom is the "neck" rule (see for instance this article): if your symptoms are above the neck then you can train; if they're below the neck you can't:
David Nieman, Ph.D., who heads the Human Performance Laboratory at Appalachian State University, and has run 58 marathons and ultras, uses the "neck rule." Symptoms below the neck (chest cold, bronchial infection, body ache) require time off, while symptoms above the neck (runny nose, stuffiness, sneezing) don't pose a risk to runners continuing workouts.

This view is supported by research done at Ball State University by Tom Weidner, Ph.D., director of athletic training research. In one study, Weidner took two groups of 30 runners each and inoculated them with the common cold. One group ran 30 to 40 minutes every day for a week. The other group was sedentary. According to Weidner, "the two groups didn't differ in the length or severity of their colds." In another study, he found that running with a cold didn't compromise performance. He concluded that running with a head cold--as long as you don't push beyond accustomed workouts--is beneficial in maintaining fitness and psychological well-being.

The relevant paper is here. Most of the people I know tend to stick to easy distance and avoid hard workouts like intervals. I don't know of any science supporting this theory, though.

This NYT article, sent to me by Eu-Jin Goh, also describes another study that indicates that colds don't impair exercise performance:

The studies began, said Leonard Kaminsky, an exercise physiologist at Ball State University, when a trainer at the university, Thomas Weidner, wondered what he should tell athletes when they got colds.

The first question was: Does a cold affect your ability to exercise? To address that, the researchers recruited 24 men and 21 women ages 18 to 29 and of varying levels of fitness who agreed to be deliberately infected with a rhinovirus, which is responsible for about a third of all colds. Another group of 10 young men and women served as controls; they were not infected.

At the start of the study, the investigators tested all of the subjects, assessing their lung functions and exercise capacity. Then a cold virus was dropped into the noses of 45 of the subjects, and all caught head colds. Two days later, when their cold symptoms were at their worst, the subjects exercised by running on treadmills at moderate and intense levels. The researchers reported that having a cold had no effect on either lung function or exercise capacity.

This actually is a fairly surprising result. Most athletes certainly feel their performance suffers when they're sick. I certainly feel worse training when sick, and while I haven't taken any measurements of lung capacity, I do notice that my heart rate is significantly higher. If anyone has access to the original paper, I'd be very interested in reading it. (Abstract here). Initial impressions: the sample size is pretty small. I'd be interested in seeing a crossover study. What about performance at strength exercises?


December 24, 2008

I recently read Hanna Rosin's piece in The Atlantic about transgender children. The subjects of the piece are children who, from a very young age (< 5) insist that they are—or want to be—the other gender. Even for parents who are basically cool with the concept of the transgendered, this seems to still require some pretty difficult decisions. My take home points from the article go something like this:
  • The current state of sex reassignment (yes, I know that some trans-people prefer the term "gender confirmation surgery", but as far as I know, sex reassignment is still the standard term) technology isn't that great. Certainly, a post-treatment female (i.e., someone who was born male) isn't as much like a biological female as you would like.
  • Sex reassignment treatment works a lot better if you haven't gone through puberty yet.
  • It seems fairly problematic to let children this yound make judgements about something as irreversible as having their genitals reconstructed. Moreover, according to this Endocrine Society review, a significant fraction of children diagnosed with Gender Identity Disorder (GID) experience spontaneous remission post-puberty.
  • There are treatments available which will block/delay puberty, so at least the children are old enough to have a better chance of making their own decisions, though if it's puberty itself that realigns the child's psychological identity with their biological identity, it's not clear that helps as much as you would like. Anyway, if that happens, you can just stop the hormone blockers and let puberty proceed normally.
  • The children in question seem much happier when they're allowed to dress and act as the gender they want to be.
  • There are some psychological treatments which may (or may not) increase the chance that the child will become happier with their biological identity, but they sound pretty uncool (e.g., encouraging extreme traditional gender roles), and after reading the Atlantic article, I came away with the impression that the treated children weren't that happy as adults. But this seems inconsistent with letting them assume their desired gender roles in the interim.

One more note: some of the children in this article seem to have adopted stereotypical opposite sex behaviors incredibly early (like 2-3 years old.) I don't know what that tells us about how preferences for such behaviors get determined, but it's interesting.


December 5, 2008

The Times reports that H.M., a name familiar to generations of psych undergrads, has died. H.M. was a patient who underwent surgical treatment for a seizure disorder which left him unable to form new memories (think Memento but without the tattoos and the ultraviolence.) This made him a popular subject for the study of memory. One of the most interesting features of H.M.'s condition was that he could learn some new physical skills without being conscious of it. When presented with the task he would claim never to have tried it before, but would be able to perform them anyway. The Wikipedia article and the Times obit both make good reading.