Mark Cucuzzella MD, Professor West Virginia University School of Medicine, LtCol US Air Force
2006 and 2011 Air Force Marathon Champion and Air Force Marathon Team Member since 1988
So how does this apply to you in your Boston Marathon, whether you are going to run 2:20 or 4 hours plus?
As you enter the weeks prior to the race here are a few strategies to help you set your plan. Running your best marathon is part art, science, guts, faith in what you can do, and a little luck. Running your best 10k is mostly about fitness. The best analogy I can think of is this: if you have trained your body properly with the right mix of aerobic level training and some up tempo stuff in recent weeks, you have built your efficient hybrid engine ready to race the marathon. Many of you have driven in a Prius and watched the subtle shifts between gas and electric on the screen. You do not perceive these shifts. Your engine(muscles) runs on a mixture of gas and electric, and how much of each depends on the effort. This is why slow aerobic training is critical for marathon success, you build a massive electric engine.
You are starting the race with one gallon in the tank- assuming you have eaten a nice meal the night before with a breakfast top off.
- If you are in all gas mode, your engine will run about 1.5 hours at a strong pace….then you are out of gas.
- If you are mostly electric you can run all day, but maybe not so quickly.
- If you are using the proper mix you will go quick and efficient for duration of your event, and you can even do some topping off along the way.
The glucose utilizing pathway (glycolysis for the science folks) is the gas. This is your stored liver/muscle glycogen and blood glucose (pasta meal and breakfast) – easy to access for ready energy. The fat utilizing pathway (gluconeogenesis for the science folks) is the electric. In marathons you must be in hybrid the entire race. Hybrid is where your energy (ATP) is coming from both sources.
Many runners are in great “10k shape” (an all gas event), then run their marathon in the gas mode- and usually crash. Glycogen sparing strategy need not apply in races of less than an hour as long as you had a good pre-event meal to fill the tank. In marathons and ultras- top end fitness matters little and can only be applied very near the finish. Glucose gives 36 ATP per molecule, fat 460 ATP per molecule. You must tap into the fat burning tank. Now you know how a bird can migrate 7000 miles without a Powerbar.
Tomorrow: So how do you know you are running in your best hybrid mode