Never "Hit the Wall" Again

Do you know how much energy you require to finish a marathon within your target time?  Benjamin Rapoport does.  Rapoport, an M.D./Ph.D. Student at the Harvard-MIT Division of Health Sciences and Technology has created a series of equations to do just that, figure out the amount of 'carb loading' one should do prior to a marathon so that they avoid 'hitting the wall'.  For anyone unfamiliar with the term 'hitting the wall', it is the point during the race where your body has used all its stored energy (in the form of glycogen) and cannot continue to work since no energy is available.

Rapoport states that 3 factors influence when an individual will 'hit the wall'.    These 3 factors are: your VO2 max (aerobic capacity), your relative exertion, and the amount of glycogen (energy) stored in your leg muscles.  You can painstakingly do all the math yourself, or use the free online calculator at www.endurancecalculator.com.  All you need is your age, weight, and resting heart rate.  You have the option of inputing your VO2 max, but not many know it off hand.  Testing for such a value is expensive (thanks to school I have had the opportunity to know mine, 60mL/kg/min as of April 2011).

Here's what the calculator suggested for me:

Running Endurance Calculator Results (Marathon)

Basic Information
Estimated Maximal Oxygen Uptake (VO2max) (in mL oxygen per kg body mass per minute):	60
Total Energy Required to Run a Marathon (in kcal or food calories):	3157

Conservative Best Marathon Performance (Normal Glycogen Levels)
Time:	3:12:31
Mile Pace:	7:20
Kilometer Pace:	4:33
Carbohydrate Loading Required (kcal):	1656

Aggressive Best Marathon Performance (Maximal Glycogen Levels)
Time:	2:12:03
Mile Pace:	5:02
Kilometer Pace:	3:07
Carbohydrate Loading Required (kcal):	2999

Target Marathon Performance
Time:	3:00:00
Mile Pace:	6:51
Kilometer Pace:	4:15
Carbohydrate Loading Required Prerace (kcal):	1836
Minimal Fueling Required During Race (kcal):	0

Now the disclaimer: carb loading is not the magic ingredient to going faster, smart training is.  The website states 'carbohydrate loading will not guarantee an increase in speed, but it can ensure that a runner will not hit the wall at his or her chosen speed'.

...Darn.