MONITORING IRONMAN PERFORMANCE
Dr Stephan Athan of the University of South Florida had a research study planned that involved competing in the Hawaii Ironman October 3. He had planned to test a device he helped develop to measure physiologic conditions using non-invasive spectrophotometry. The device consists of a sensor connected to his finger that measures the concentration of hemoglobin in his blood and relays it to a small computer carried on his body. He had even arranged for data to be transmitted to the Internet. Ferret was all set to follow the triathlon but has just found out that the study has been postponed.
Prior to learning of the postponement, Ferret consulted Prof. Tim Noakes of the Sports Science Institute of South Africa about the ability of this device to monitor dehydration. According to Noakes, the concentration of hemoglobin gives "a reasonable measure of overall dehydration only in those athletes who do not ingest sodium during a race. Plasma volume contracts in proportion to the loss of sodium from the body; if there is additional fluid loss, it will come from the intracellular compartment." In other words, Athan will know if his blood runs short of water, but maybe not his muscles.
Noakes feels that there are problems more important than dehydration in ultra-endurance events. He suggests that a probe for body temperature would be valuable. He also thinks that damage to the weight-bearing muscles is important, but it's not clear how you'd monitor it or do anything about it. (See also the ACSM conference report on endurance performance in the heat.)
Contributed by Mary Ann Wallace.
As Ferret gets ready for October and the baseball World Series, she wonders how Little League baseball players acquire their skills. Do they just naturally know how to coordinate the movements of the bat and their body to successfully hit the ball?
Fortuitously, Ferret recently read a review article on implicit and explicit learning of motor skills (Magill, 1998). Implicit learning is learning without awareness, or using "unconscious" methods to perform a skill. Explicit learning is a conscious, deliberate awareness that typically applies strategies provided by a coach or instructor. The article outlines several methods and practice conditions that facilitate implicit learning of skills.
Ferret suggests that this information can be applied to all sorts of open motor skills, but she is certain you could use some of these techniques to help your Little Leaguers hit the ball better!
Magill, R.A. (1998). Knowledge is more than we can talk about: Implicit learning in motor skill acquisition. Research Quarterly for Exercise and Sport, 69, 104-110.
Contributed by Trish Shewokis.
What do St Louis Cardinals' home-run hitter Mark McGwire, Pittsburgh Steeler's offensive tackle Paul Wiggins, Olympic swimmer Michelle Smith de Bruin, shot-put champion Randy Barnes, and sprinter Dennis Mitchell have in common? Role models for young athletes wanting to be famous. But what kind of role models? Mark McGwire openly acknowledges supplementing with androstendione; the others are suspected of doping offenses.
Because it's found in the pollen of Scotch pine trees, androstenedione is classified as a dietary supplement by the US Food & Drug Administration. Hear the term dietary supplement and it surely can't be as bad as they say, can it? Yet it is banned by virtually every major sport. Andro as it is commonly called, has been the subject of a recent article in the New York Times.
In the body, andro converts to testosterone and stimulates muscle growth and sex drive. But like other steroids, used in high doses it has serious side effects that are less publicized: increased risk of prostate tumors, clotting disorders, liver problems, uncontrolled aggressive behavior, baldness, acne, and breast growth in men. For young people it can have a negative effect on bone growth.
How do we send convincing messages to young athletes that good training and good nutrition are more important than playing roulette with their health and sporting careers? Dr Linn Goldberg and colleagues might have the answer: their 3-year program involving 3200 students lowered first-time use of anabolic steroids by 50%. They made their point with graphic illustrations of the less publicized effects of long-term use of steroids.
Goldberg, et al. (1996). Effects of a multidimensional anabolic steroid prevention intervention: the Adolescents Training and Learning to Avoid Steroids (Atlas) Program. Journal of the American Medical Association, 276, 1555-1562.
Angell, M. & Kassirer, J. (1998). Alternative medicine--the risks of untested and unregulated remedies. New England Journal of Medicine, 339, 839-841.
Contributed by Mary Ann Wallace.