New to marathons - avoid hitting the wall calculator

heybales

So how do you finish a marathon without hitting the "wall", and not just chuck down energy gels every 2 miles? Or go at such a slow pace as to avoid the problem? Ok, those are perfectly valid schemes, but if pace and food intake could help, why not!

So some interesting research and calculator to assist in avoiding the "wall" where glucose stores mostly ran out and body has switched over to converting other things, mainly muscle, to glucose for use. Fat still being used of course.
This isn't super recent, but I'd never seen it before on here through Search function.

Article also mentions the one method of carbo-loading that actually actually shown some results, lest you think the big pasta dinner night before is really accomplishing much besides storing excess carbs as fat. More on that below.

So this is main study, and full of details on mid-race fueling facts, carb loading facts, energy usage, ect.
http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1000960

If you want a synopsis of it that is tad easier to follow. Oh, I love how the author twisted the facts of what happens at the wall to mean you ran out of glucose and switched to burning fat, as if fat hasn't been burned the whole time anyway.
http://www.newscientist.com/article/dn19614-formula-for-the-perfect-marathon-carb-load.html

Since the calculator works best with a known VO2max figure, here are couple ways of figuring that out decently. Simple with calculator, and fun on treadmill. Take your pick. Fun might not be the best word there, but anyway...
http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max
http://www.myfitnesspal.com/topics/show/577839-hrm-s-with-vo2max-stat-improve-calorie-estimate&nbsp

And the main calculator for pace and eating strategies to make it!
http://endurancecalculator.com/


Easy explanation and method on carb loading, even if not what studies have shown is best. For those here eating deficits, be aware of weight gain you need to have happen if doing it right.
http://www.runnersworld.co.uk/nutrition/60-second-guide-carb-loading/3961.html

And from the study, more detailed method. Is this useful? Look at that gain in glucose stores possible!
[qoute]
All of these techniques are variations on a three-phase theme: Prolonged or high-intensity exercise of the muscles to be loaded, typically followed first by a period of dietary carbohydrate restriction, and then ultimately by a period of high carbohydrate intake. Such schedules are designed to induce a ‘glycogen supercompensation’ effect, whereby glycogen depletion and carbohydrate restriction stimulate increased expression of glycogen synthase in the depleted muscle fibers, enhancing their ability to synthesize glycogen during the final, high-carbohydrate-diet phase, permitting muscle fibers to store glycogen in supranormal concentrations. Exercise-induced suppression of insulin and muscle-contraction-induced activity of muscle glucose transporters also facilitate glycogen loading specifically in the target muscles, in preference to fuel storage in other physiologic energy stores such as adipose tissue and nonworking muscles. Biopsy studies of leg muscles loaded in this way indicate that while the muscles of trained athletes typically store glycogen at a density, , of approximately 110 mmol glycosyl residues per kilogram (), glycogen loading protocols can increase that density to a maximum of approximately 200 mmol glycosyl residues per kilogram () [23]. While the maximum size of the glycogen reservoir available to an endurance runner depends on the size of the relevant muscles, it is possible to estimate the amount of accessible glycogen: A lean, male runner, for example, may be 45% skeletal muscle by mass, with half of that mass in his leg muscles; at 70 kg such an athlete would typically store 310 g of carbohydrate as muscle glycogen, and could store at most approximately 570 g, corresponding to approximately 1250 and 2270 kcal of leg muscle glycogen, respectively.
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Interesting compare to my past performance, I did do the Maffetone method of slowing down to speed up and try to train fat usage, did my first marathon in 8:30 pace, and no supplements or wall. The calculator at that past self (unknown VO2max) does show as not needing any mid-race fueling. Huh.

Hope you can find useful for your pacing and food eating levels for your training and race.

arc918

I would suspect most runners on this site don't have the patience to build base through low heart rate training (Maffetone). I know I don't.

I've seen people have a ton of success with Maffetone, I just can't deal with slowing way down to make it happen.

heybales

I would suspect most runners on this site don't have the patience to build base through low heart rate training (Maffetone). I know I don't.

I've seen people have a ton of success with Maffetone, I just can't deal with slowing way down to make it happen.

Oh, I hope you don't think that whole thing had anything to do with Maf, that was personal comparison between what I had done, and what the calculator said I maybe could have done.

That is mainly NOT about training, but race pace and how much to pre-load and during race eat.