At the moment, I only use live subjects for the 'experiments' in my basement exercise physiology lab but just in case I ever lose the plot entirely and decide to put together some hybrid of body parts to construct my ideal triathlete to contend in Kona, here’s what I’ll be on the lookout for…
Skeleton: My Kona monster will have a light, ‘small boned’ skeleton of average proportions. He will be relatively tall (~1.8m) in order to:
a) Have a sufficiently long vessel & long arms to be relatively hydrodynamic in the water.
b) Have a sufficiently large surface area:body weight to dissipate large amounts of heat; ~1380W of heat energy on the bike (@290W) and 1180W of heat energy on the run (@2:40 marathon pace).
c) Have a sufficiently large thorax able to hold the engine capable of powering that 290W on the bike.
However, he will also need to be quite light for this height in order to run that 2:40 pace. Under 70kg total (BMI~21.5). To accommodate the weight of the necessary muscle & organ mass to produce the requisite power numbers, the skeleton would have to weigh only approximately 5.5kg, i.e. a very light frame.
Some distinctive features of this frame:
- Average to short total leg length with relatively long femurs – lower leg length approx. equal to (not significantly greater than) femur length (=decreased bike frontal area without sacrificing leverage/power)
- Relatively wide arm span (equal to or greater than standing height) with average shoulder width, i.e. long arms (=smaller frontal area on the bike without affecting swim economy)
- Small to average size feet (=better run economy & decreased FA on the bike)
All in all, my monster will need a frontal area at or below 0.39m^2 to put in a competitive bike split at 290W. He will need the bike and body geometry to achieve this.
Muscle: “Konie” will have sufficient leg muscle mass to generate ~290W over the bike course. In normal Kona conditions, this represents about as much power as an athlete of this size can generate without overheating. In this case, more is not better. Assuming that his VO2max power would need to be ~400W/5.4L to do so, at 200ml/kg of muscle this would equate to 27kg of appendicular mass. On normal (triathlete) distribution, ~20 of this 27kg of muscle would be distributed to the legs and ~7kg to the arms.
Cardiovascular system: To fuel 400W of power at VO2max is going to take a significant amount of O2. Somewhere in the range of 5.4 liters per minute. Assuming an a-VO2 extraction of, 16ml/dL, my Kona monster’s cardiac output is going to need to be 34L/min, or at a max heart rate of 180bpm, a cardiac stroke volume of ~190ml, in other words, ‘a big ticker’.
Bodyfat: Doing the math, Kona Monster is going to need to be pretty lean. At 5.5kg frame mass, 27kg of appendicular muscle and a likely visceral/organ mass of ~33kg (average for someone of this frame), total fat mass can only be ~4.5kg or ~6% bodyfat.
Overall: Konie’s somatotype will be a small meso-ectomorph (1.4/3.7/3.5)
Other: I will also require a set of jumper cables to get this bad boy started :-)
If you want to see how you stack up compared to “Konie” a DEXA scan coupled with a standard anthropometric assessment (girths and breadths) will give you some insight.
Choose your parents (or your sport) wisely & if you see me coming at you with a tape measure, run the other way :-)