BMI = (gewicht in kilogram) :
(lengte in meter X lengte in meter) bijvoorbeeld: BMI = 66,3 : (1,8 X 1,8) |
WHR = (omtrek van je middel in
cm) :
(omtrek van je heupen in centimeter) bijvoorbeeld: WHR = 90 : 75 = 1,2 (man, zwaarlijvig) aanbevolen WHR voor vrouwen is <0,80 aanbevolen WHR voor mannen is <0,95 opmerking: omtrek van je middel meet je in ontspannen houding, smalste deel van je middel BOVEN je navel |
vet% = (BMI X 1,2) + (leeftijd X
0,23) - (geslacht X 10,78) - 5,4 |
Beste, Het vastleggen van normen voor vetpercentage is inderdaad omstreden, zeker als het om jongeren gaat. Vetpercentages voorop stellen van 12 tot 15% is onverantwoord en bovendien zinloos. Het bepalen van de lichaamssamenstelling bij jonge zwemmers is een manier om aanpassingen van het lichaam aan training, ontwikkeling, enz. op te volgen. De Amerikaanse zwemfederatie heeft op haar site een interessant artikel hierover, met een uitgebreide referentielijst. De Vlaamse erkende keuringscentra benadrukken in hun voedingsrichtlijnen voor sporters het belang van het controleren van de energiebalans en waarschuwen voor een overdreven fixatie op gewicht en vetpercentage. |
Geachte, Zonder enige twijfel houdt dit advies gevaren in, ik ben dan ook blij te horen dat personen zoals u dit opmerken. Wat precies de adviezen zijn voor topsporters weet ik niet precies, wij gaan in ieder geval uit dat bij jonge meisjes de BMI tussen de 19-25 moet liggen met een vetpercentage rond de 20%, Er zijn wel sportartsen die zich specifiek met deze problemen bezig houden, wij zelf zijn uitsluitend bezig met de eetstoornissen mvg Prof.Dr. Myriam Vervaet University of Ghent Department of Psychiatry and Medical Psychology |
Swimming is a tough sport to get into for a lot of runners. Runners do not have enough body fat, especially in their legs, to help them float in the water. ... |
HOW EATING
DISORDERS AND DISTURBANCES INFLUENCE
By Lisa
Franseen, Ph.D., Clinical Sport Psychologist
MYTH & TRUTH The thinner I am, the better I'll perform. As I've discussed, athletes who are too thin can fail to perform well. The thinner I am, the stronger I am. There are more thin people who are physically weak than there are thin people who are strong. Being "thin" - a very subjective term which tends to mean "not weighing much" - is no guarantee of the amount of muscle mass on one's body. When I lose weight, I lose fat. When people lose weight, they often gain body fat while losing valuable muscle mass. Eating foods that contain fat will put fat on my body. What we don't ingest, our bodies tend to keep. If we don't drink water, our bodies hold onto water. If we don't eat fat, our bodies hold onto fat. Body fat is related to the quantity of calories ingested, not the quality of calories. If I don't perform well it's because I am not thin enough. This may be the strongest myth alive. Poor performances are more often due to weak mental skills, lack of physical skills, poor nutrition, outside stresses, not enough sleep, etc. Many females automatically assume they performed poorly because of their weight but there are lots of "thin" athletes who perform poorly, too. Having less than 10% body fat is best. It is absolutely essential to have at least 11% body fat for normal physical development, mensus, and prevention of osteoporosis.
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Back to
basics: improving swimming fitness by David Pyne (swimcity.com)
Another way
to reduce resistance and drag is to reduce body mass (weight). While
this is
obviously a big factor in sports such as distance running, the
circumstances
are different for swimmers. Weight
reduction is not as important in swimming
because the body mass is subject to buoyancy by being immersed in water.
Differences
in swimmers’ individual body builds could play a significant role in
determining whether or not weight loss improves swim performance.
The
physiological effects of reducing body mass also need to be considered. Some
swimmers feel weaker and more prone to fatigue, illness and injury when
their
body weight falls below a critical threshold. |
WHAT’S FAT GOT TO DO WITH FAST? - 14/09/2001
It makes floating
easier, but does body fat make you
faster?
Our body composition works against us in unexpected ways. We’re built to be balanced and stable on land with lots of mass and length below the waist, mostly volume above it. So where do we sink? Right: hips and legs, while we’re very buoyant between the armpits. |
Coaching Strategies
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