Carb loading before a marathon is an essential way to build your energy stores prior to the big race. The body relies heavily upon these stores for a successful race. Pushing yourself through several hours of hard or even moderate running will deplete your energy more quickly than you think. While many runners carry gels or chews for a pick up during the run, these are not enough to refuel when you are running on empty. Effective carb loading for a marathon begins several days prior to the run, not the morning of it. Glycogen stores can only hold you for about 90 minutes of hard running. Beyond that, your body may become depleted and you may become acquainted with the infamous wall… which is not something you want for your long run.
What to Eat
Not all carbs are created equal. Do not expect to fill up on foods that are 90% junk starch and be 100% prepared and carb loaded for your race. Carbs need to come from complex sources, such as whole grains and pastas. Snack foods should include granola bars, quinoa, oats, brown rice, healthy sugars from fruits and whole grain bread. Bread that is heavy, dense and nutty is the best source. Pasta should be hearty and made from whole grains. I cannot stress enough how important it is to balance your protein intake with your carbs; protein keeps your muscles going strong in repair mode. Leaving it out will make your muscles work harder to repair after workouts, and deplete your glycogen stores faster.
How much to Eat
A good rule of thumb for effective carb loading may look a lot more intense than you are prepared for… eating 7grams of carbs per kilogram of your own weight each day adds up. However, if you can manage this (and still balance your protein intake) you will find yourself well prepared for race day.
Snack often, but do not use these as meal replacements. Carbs store better in the body when they are eaten. Drinking carbs can cause your body to throw the baby out with the bathwater; focus on hydrating rather than carb loading with your liquid intake.
Watch what you Eat the Day of the Race
Do not attempt to carb load the morning of your race unless you want to experience tummy trouble or several stops to the bathroom along the course. Typically, I eat a bowl of oatmeal or a piece of toast with a banana and a handful of pistachios on the morning of a marathon. I also snack on half of a Cliff bar on my way there. This, combined with my carb loaded meals during the 2 weeks prior to the race allows me to avoid the wall around the 20 -22 mile mark.
If you think you may be overdoing your carb loading prior to the race, chances are you are actually on the right track. Running experts estimate that only 12% of marathon runners consume enough carbs to effectively store up their glycogen prior to the marathon.