Welcome back to This Month in Journals! This is our occasional series surveying the world of sports science and trying to extract tidbits of research that might be of interest to the skiing public. Previous editions can be found here: December, October, and September.
– The British Journal of Sports Medicine dedicated several articles to electrocardiograms, which help doctors detect heart conditions – such as the one encountered by Marit Bjørgen which kept her from competing at the Tour de Ski. As the journal notes, sudden cardiac death is the most common cause of fatalities in sport, and more efforts should be made to assess the risk to athletes.
(Awareness is a big issue: reportedly, after the death of Norwegian swimmer Alexander Dale Oen gained international attention in April, the Norwegian ski team was offered comprehensive cardiac testing, but turned it down.)
But a big challenge is how to interpret these workups performed on elite athletes, whose cardiac behavior is completely different than your average couch-potato – or even a weekend warrior. A group of physicians who had met in Seattle to draft guidelines on how to interpret athletes’ electrocardiograms reported on their findings, including a list of abnormalities that are actually adaptations to training.
Other articles discussed the fact that men are more likely to have a sudden cardiac death instance in a running marathon than women are (some are able to be resuscitated), and how to best screen adolescent athletes.
– Forget doing a threshold test with a breathing tube over your face, tracking your morning heart rate, and getting pricked in the finger for blood lactate measurements – while those techniques for monitoring training will always be around, there’s a new kid on the block, and it’s spit.
That’s right, researchers from the Federal University of Uberlandia in Brazil reported in the International Journal of Sports Medicine that they were able to use two markers in saliva samples to measure elite swimmers’ progression through a several-month training block. At the training load accumulated, more and more nitrous oxide was found in the athletes’ saliva samples, and less and less of the protein alpha-amylase.
This works partly because training day in and day out tires the body and decreases sympathetic nervous system function (the “fight or flight” mode that stresses the body) and ramp up parasympathetic activity (which allows rest and recovery). Alpha-amylase is regulated by the sympathetic nervous system, so it’s not surprising that levels decrease as training gets tough.
The authors believe that as a result, saliva can be used to track how well the body is handling the stress of a training block, whether training is progressing as expected, and whether athletes are sufficiently recovering. So get ready for your coach to start swabbing under your tongue.
-A bevy of small articles tackled specific topics near and dear to skiers’ hearts. Here are a few.
First, a team of researchers from Trondheim, Norway, tested endurance performance at a range of temperatures while nine athletes were wearing cross country ski suits. Allowing their nine skiers to wear wind briefs and long underwear under their suits, researchers put them through all-out running tests on a treadmill at six different temperature regimes in a climate chamber.
Publishing their findings in the European Journal of Applied Physiology, the researchers predictably found that the athletes’ skin cooled more and faster at lower temperatures (for instance, -14 degrees Celsius). But they also found that VO2Max and time to exhaustion were optimized at “moderate” temperatures: between -4 and 1 degree Celsius.
Writing in the journal Medicine and Science in Sports and Exercise, a team led by Bath, UK, researcher Oliver Peacock reported that taking nitrate supplements did not increase performance in cross country skiers. Previous research had shown that nitrate could reduce the oxygen cost of hard exercise, but the team found that while nitrate levels did rise in the blood after taking a supplement, skiers did not perform any better in a five kilometer running time trial.
Finally, a group from Oslo and Ås, Norway, looked at interactions between wild reindeer (Targus tarandus tarandus) and skiers and snow-kiters. Noting in Applied Animal Behavior Science that reindeer have a much longer fright reaction to snow-kiters than to skiers who stay confined to their own trails, the team used field data to build models of how these interactions would affect feeding habits. Previous research suggested that disturbing reindeer decreases the time they can spend grazing, which in the winter can be detrimental to a herd.
As it turned out, an increasing number of snow-kiters reduce the reindeer feeding time to zero as they spend all their time avoiding the crazy contraptions, while skiers on set trails hit a threshold after which the reindeer reduce feeding time by 7.5%, and simply stop crossing the ski trails. The group suggested that reindeer welfare be taken into account when planning ski trails or allowing alpine areas to be used by ski-kiters.