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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.
ACQUIRING SKILLS
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.
WORTH THE
RISK?
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.