Welcome back to our almost-monthly series, this month in journals! One of the most visible developments in the last month has been that the British Journal of Sports Medicine devoted an entire issue to the 2012 Youth Olympic Games in Innsbruck, Austria. This was the result of the journal’s partnership with the International Olympic Committee’s medical commission. The cover featured biathletes skiing up a hill.
Inside, an editorial explained how the organizing committee is taking an academic approach to examining long-term legacies for athletes and others involved in the event, which is especially important as the Youth Olympic Games is a new series and can be adapted and improved in the future. Specific articles examined how relative age, quality of life, coaching behavior, and parental involvement affected competition.
Most of the health-related research concerned either alpine skiing or snowboarding. However, the journal also published a large-scale review of health services at the Games, which is important because there has been little study of how to deliver medical care at youth sports events of this size, compared to assessing adult athletes.
“As injury risk and patterns of young elite athletes may vary from their older professional counterparts, injury surveillance of young elite athletes is needed to gain knowledge about the injury risk among this highly competitive population,” the University of Innsbruck team wrote.
They found, using the IOC’s injury surveillance system and other techniques, that 11 percent of athletes had an injury of some sort during the Games, while nine percent got sick. Of injuries, 60 percent occurred in competition and 40 percent in training. Most injuries occurred in alpine skiing, snowboarding, ski cross, and hockey; six percent of cross country skiers, six percent of nordic combined skiers, and one percent of biathletes reported an injury.
Nordic skiers were not so lucky in the illness department, with ten percent reportedly getting sick. The overwhelming majority of these cases were respiratory illnesses.
Recommendations included efforts to remove stress and competitive anxiety for young athletes, with the hypothesis that these mental and emotional challenges create an environment where injuries are more likely. The team also asked whether young athletes were as well-equipped to handle multiple high-pressure competitions in a short time span. Finally, they noticed that girls were almost twice as likely as boys to get sick and recommended gender-specific strategies to keep young athletes healthy and competing.
* Elsewhere in news about youth, a Norwegian study in The Scandinavian Journal of Medicine and Science in Sports found that high school students are less fit that they used to be. Using nearly 5,000 test results from 3,000 meter running tests (something intimately familiar to nordic skiers…) collected over 40 years at two high schools, researchers in Stavanger, Norway, found that boys’ running times have increased by 10 percent and girls’ by six percent.
However, all hope is not lost for Norway. The fastest runners are not much slower than they were in the late 1960’s; it’s the slowest decile of runners that has lost the most ground. The authors correlated their findings to other studies showing the similar patterns across Europe, as well as to rising BMI and lower levels of physical activity in some segments of the population.
“The aerobic fitness decline for the least aerobically fit pupils is comprehensive and is alarming as physical activity and aerobic fitness are inversely associated with metabolic risk and low aerobic exercise capacity is a strong predictor of mortality in adults,” the team wrote. “This increasing gap in aerobic fitness among pupils can result in a larger class distinction in physical fitness and health.”
* There has been debate for years about whether stretching before exercise improves performance, and if so, what kind of stretching. This month in the same journal, a team led by Dr. Fabio Esposito from the University of Milan tackled a common target in the debates, static stretching, and used it to assess cycling performance. The team noted that most previous studies had used running, but cycling recruited different muscles and even different types of muscle fibers, and that the impact of stretching might be activity-specific.
Using nine men as subjects, the team administered VO2Max tests and 85-percent effort tests with and without passive stretching. The stretching protocol focused on lower-body muscles and consisted of several rounds of 45-second stretches, using a force (for instance, the assistance of another person) to stretch the muscle to the point of discomfort before allowing 15 seconds of recovery.
The team found that athletes were more flexible after stretching, but that stretching did not affect their VO2Max outcomes. However, the men took less time to reach exhaustion in the 85-percent trials after stretching than they did without stretching – by a whopping 26 percent. Cycling efficiency decreased over the course of the test for both conditions, but more markedly after stretching.
“These results are compatible with stretching-induced alterations of the motor unit recruitment pattern and utilization, and with changes in muscle–tendon unit mechanical and viscoelastic characteristics, leading to a less efficient system,” the authors concluded. “From a practical point of view, these findings suggest that care must be taken in administering stretching immediately before an endurance task… stretching can affect not only maximum strength but also heavy-intensity aerobic exercise.”
* In a study that examined the same general topic – use of different types of muscles and how they affect exhaustion – a team based out of Salt Lake City and Verona, Italy, examined the tolerance level for fatigue when using small muscled versus large muscle groups. In Acta Physiologica, they compared biking to knee extensions, and found that subjects could perform knee-extension exercises for longer than biking before becoming exhausted.
Wait, you might say – that’s clearly because extending your knee is easier than biking. That’s true, to an extent. The team also found, however, greater changes to the muscles’ ability to contract following the knee extension sessions, and using stimulation of the femoral nerve saw that the muscles were actually more fatigued.
The implication, they wrote, was that using small muscle mass exercises, an athlete can achieve a higher workload and level of fatigue before the body’s tolerance limit is reached – the sensory system doesn’t pick up on the fact that it is tired. To get muscles to adapt to exercise, it may be beneficial to sometimes work on muscle-specific activities, not only on doing the entire activity for which you are training.
Chelsea Little is FasterSkier's Editor-At-Large. A former racer at Ford Sayre, Dartmouth College and the Craftsbury Green Racing Project, she is a PhD candidate in aquatic ecology in the @Altermatt_lab at Eawag, the Swiss Federal Institute of Aquatic Science and Technology in Zurich, Switzerland. You can follow her on twitter @ChelskiLittle.