Glycogen Loading Before a Marathon – How To Get Ready To Run

You’ve put in the time. You’ve logged the miles. You’ve made social sacrifices and pushed your body to the limit for months and now finally, the day is almost here… That’s right. It’s Marathon season.  

At Integrative Spine & Sports, a sports medicine practice in New York, we talk to runners all the time. Whether this is your first big race or you’re a grizzled veteran, it’s essential to have a plan, to take unnecessary mystery out of final prep.  You know all about tapering training runs, but it can be confusing to know how to maximize nutrition in the final weeks. How much should you eat?  And what kind of foods and nutrients will help you achieve your personal best?  

There’s plenty of conflicting information available and sorting through the noise can be overwhelming when all an athlete really wants to do is focus on running.  

Throughout your training period, you’ve maintained a consistent, balanced diet – You’ve eaten whole grains, healthy fats, good sources of lean protein and plenty of fruits and vegetables.  But a marathon is unlike any other race else.  To truly maximize your potential it helps to understand how the body uses food for fuel.  

After a meal, the body stores calories, specifically carbohydrates, in the muscles as glycogen.  When you exercise, your body burns the glycogen, breaking it down into easy to use glucose. The harder you run, the more glycogen you use.  

As your muscles run out of glycogen, your body searches for another source of energy and begins using fat as fuel.   But fat burns less efficiently than carbohydrates, so eventually the body begins to slow down. During a marathon, that’s a problem.  

Runners overcome this inefficiency by learning to manage their glycogen stores. The goal is to trick the body into storing as much glycogen as possible. To achieve this, doctors and nutritionists recommend a specific regimen leading up to the day of your race.  

Start by completing a long run a week before the marathon. This final distance session will deplete the body’s glycogen stores and you will hunger for carbohydrates.   But rather than give in to the craving, commit to a low-carbohydrate diet for three days, keeping the glycogen levels as low as possible. This will send a signal to your muscles to store as much glycogen as they can.   

Then, over the following three days, load up on complex carbohydrates. Ideally, 60-70% of your overall calories should come from carbs.  Pasta, potatoes, rice, cereal and fruit are all good choices, but almost anything will do. Drink lots of fluids and get plenty of rest and let your glycogen-starved body take care of the rest.

Carbohydrates will be stored in your muscles as extra glycogen, ready to propel you 26.2 miles to the finish line.