Uh oh, you better duck kid, the first few responses might be a little rough.

;-)

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Behold the turtle! He makes progess only when he sticks his neck out. (James Bryant Conant)
GET OFF THE F*%KING WALL!!!!!!! (Doug Stern)
Brevity is the soul of wit. (William Shakespeare)

Andy,

welcome to Slowtwitch, and let me be the first to offer you a smartass remark. IM distance is 2.4, 112 and then a mary.


And to answer your question, training and huge balls. I have never done an IM, but several things that are physically grueling. Those are the only 2 ways. Less of one means you need more of the other.

Whats Homeostasis?

your renal system (kidneys) will reabsorb more water from urine to blood, meaning you'll lose less water to urine

your blood vessels at the surface (near the skin) will dilate, allowing the air and sweat evaporation to cool more blood

your sympathetic nervous system will impede digestion, keeping the blood in the legs/arms/lungs, rather than in the stomach/small-intestine

as you get dehydrated, your blood volume will decrease, prompting increased heart rate

your muscles will use slow, glycolytic (sp?) metabolism to turn energy stores (glycogen) into muscular contraction. as glycogen stores run out, they will start convert fat and muscle into muscle contractions... that's why we try to replenish our glycogen supplies through good nutrition

i hope this has helped a little. it's college-level stuff, and i don't know if you're in college or high school, so hopefully this will be useful.

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http://www.theninjadon.blogspot.com

"The bicycle riders drank much wine, and were burned and browned by the sun. They did not take the race seriously except among themselves." -- Ernest Hemingway, The Sun Also Rises

Try and figure out how I used to be able to consume 12 beers and survive... with a body weight of only 126lbs. Ironman is easy after that...

ooo we learned about all that this year in anat and phys.!

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maybe she's born with it, maybe it's chlorine
If you're injured and need some sympathy, PM me and I'm very happy to write back.
disclaimer: PhD not MD

With regard to energy utilization, two kinds of metabolism - aerobic and anaerobic. Aerobic metabolism is more efficient (requires less O2 to generate lotsa ATP) and uses stored fat as well as glycogen as a substrate. Generates CO2 and H20 rather than lactic acid. Long-distance tri (IM and HIM) should be predominantly aerobic, as the body has immense fat stores, and even the low-body-fat triathlete has sufficient fat stores for IM or ultra-distance races.

Anaerobic metabolism is much less efficient - can use only glucose as a substrate, and therefore has several naughty consequences: (1) breaks down muscle in a process known as gluconeogenesis to "reverse engineer" the amino acids in muscle protein into glucose; (2) rapidly depletes stored glycogen, which is found primarily in liver and muscles; and (3) produces lactic acid in addition to CO2 and H2O, which both causes discomfort locally (in the muscles) and, in the long run, can actually change the body's pH, which is a very naughty thing. In addition, anaerobic metabolism is much less efficient - it generates less energy (in the form of ATP) than does aerobic metabolism, with the same input of fuel.

One other element of homeostasis that is noteworthy is electrolyte / osmotic homeostasis. Nutrition and hydration are important in long-course because long-distance athletes can disturb their balance of electrolytes. For instance, hyponatremia (a dangerously-low level of Na+ in the blood) can result in marathons and IMs, usually from overhydration with dilute fluids (H2O) and electrolyte loss through sweat. Other critical ions (Mg++, Ca++, K+) can all be perturbed by the rigors of long course - and renal homeostatic mechanisms are often inadequate to maintain balance.

Just some additional stuff worth noting.

are you calling me a homo?!?!

The "e" is everything.

"are you calling me a homo?!?! "

lol!

i think he's refering to man-bras, gay aero helmets, leg-shaving, speedos and pink crocs.