Muscles burn Glycogen!
Glycogen is the bodies stored form of Glucose.
Conventional wisdom among endurance athletes is that eating a ton of high Glycemic foods the night before a long race will provide the fuel a runner needs to get through the race and avoid the “Wall” or “Bonk.”
Some recent research shows that there may be a better way to carb load than bagels and Pasta and that “the night before” eating may also not be the best approach.
The Night Before
Glycogen lives in your muscles and liver. The body’s total supply of glycogen can vary significantly from athlete to athlete. How efficiently uses stored glycogen can also vary greatly. Elite runners most likely are genetically very efficient at storing and burning stored glycogen. A general “rule of thumb” is that your total supply of glycogen will last about 60 -90 minutes.The time it takes to “Top Off” your Glycogen reserves also varies from person to person, but most of us need to start a few days ahead of race day.
“The biggest mistake marathoners make eating an extra-large dinner the night before the race,” says Stuart Calderwood, a senior editor with New York Road Runners (the group that puts on the NYC Marathon) and the veteran of some 56 marathons. “What they should really be doing is eating a larger-than-usual percentage of carbohydrates for the whole last three days, and then eating a normal-sized and familiar dinner.”
It may work best to add low glycemic foods to each meal you eat three or four days before the race then balance fat, protein, and carbs the night before.
Is Pasta the best choice?
A quick note on the Glycemic Index (GI). The Glycemic Index measures how quickly food raises your blood sugar level. High Gly foods like bread and pasta and most foods made from grains spike blood sugar very quickly. Whole wheat bread generally has a glycemic score of 100. Which makes it the most glycemic food you can eat. Simple carbs are converted into glucose quickly, they spike blood sugar and therefore insulin. Regular consumption of high-gly carbs can lead to Insulin resistance, d type 2 diabetes and a host of other chronic health challenges. Additionally, grains contain many anti-nutrients that block absorption of vitamins and minerals and can be pro-inflammatory.
Instead of a quick rush of glucose from a high-GI food, a low-GI food provides a slow, steady supply of muscle fuel.
One study used some blood testing to compare the effects of moderate-GI rolled oats, high-GI puffed rice or a control group who consumed plain water on endurance athletes. The subjects ate a meal with 75 grams of carbohydrate from the test food 45 minutes before performing a cycling exercise to exhaustion. The lower-GI food resulted in lower glucose at the start of exercise, but sustained higher glucose throughout the cycling exercise, indicating more glucose available to the muscles when it counted. Time to exhaustion was longer on the rolled-oats meal compared to either the high-GI rice or the control group.
Here are some examples of moderate GI foods that might work as pre-event foods for athletes:
Moderate-GI Scores (60 to 85)
Almonds and other nuts (nut Peanuts)
RX and other Paleo/ Primal Bars
Most whole fruit; grapes, mango, banana, and kiwi
Summing it up
The foods an athlete tolerates or likes, as well as the amounts, differ from person to person. Let your own experience be your guide.
It may work best to add low glycemic foods to each meal you eat three or four days before the race then balance fat, protein, and carbs the night before. In all cases the more you eat fiber-rich, nutrient dense carbs and less you eat nutrient blocking, pro-inflammatory grains the healthier an athlete you will be.