The athletic diet is as varied and particular as the athlete, and so are the tricks and manipulations in the ways we fuel our bodies for enhanced performance, endurance, strength building, and conditioning. There is no singular format for nutrient control, no set list of perfect foods, no agreed upon combination or amount of food, and no identical way of nourishment. We are individuals, and we need a personalized plan. That being said, there are certain facts that hold true in the majority of cases with minor tweaks and modifications. These are based on fundamental processes in the body and the select macro and micro nutrients that facilitate or enhance these processes. For example, to build and sustain muscle mass, protein is an essential part of the diet. To increase stamina and maintain speed and strength in endurance sports, the body needs extra glycogen which comes from carbohydrates. These are very generalized observations, but they are what allow us to build a diet plan that is perfectly suited to an athlete’s needs. If you are looking to sustain your energy through an athletic diet and keep from hitting that metaphorical wall, then you have probably looked into carbohydrate loading, but do you understand it?

It sounds easy enough. Load up on carbs. If carbohydrates create glucose, and the body uses that to maintain power, then hit up the athletic dinner and eat as much pasta as you can before the big day.

No.

This might actually do you more harm than good! An effective carb loading diet is part science and part knowing yourself. You need to know why you are doing it. What to look out for, like weight gain, and why that means you’re doing it right. What foods are good as part of a carb loading meal plan and which nutrients are best left out? How your body and digestive tract react to simple and complex carbs will determine which ones you can eat, and testing your endurance after will show you how much. Choosing to carb load cannot be a whim the week or day before your event. You need to have trial runs and make sure that this is even a conducive diet plan for your body. If you tend to avoid carbs, throwing an overload in may cause you significant gastric distress and drastically decrease your performance or take you out altogether. You’ll also need to play with timing and find effective ways to increase your glucose levels during your event. This should all be tested beforehand as to not do something that your body disagrees with when performance matters most.

Let’s take a quick look behind the science of carbohydrates to understand exactly what they do and why we need them. This will help you determine if carb loading is even necessary for your athletic pursuits.

When a muscle contracts, it needs fuel. This fuel is glycogen. Glycogen is stored up in the skeletal muscles until it is used in everyday activities or in training, workouts or athletic events. The average, healthy individual stores around 90 minutes of high-endurance energy in their muscles on a standard diet. For athletes competing at high-energy levels for longer periods of time, an increase of stored glycogen could result in a 2-3% increase in stamina. Meaning if your half-marathon time is 1:55, you could theoretically shave off 2.3 - 3.45 minutes. That could mean the difference between first and third.

Muscle glycogen tends to stay in the range of 80-120 millimoles per kilo, or 36-55 mmol per pound, of body weight. If you’re using carb loading to increase this stored energy, you can get up to 150-200 mmol/kg or 68-90 mmol/lb. This means you will need to add in seven to twelve grams of carbs per kilo of body weight, or three to five per pound, each day to build up your levels.

Let’s take a look at carbohydrates. As a general rule, we eat only a few and stick to all-natural, whole grains with a high fiber content and low sugar. This helps in the breakdown and usage of this macronutrient to avoid weight gain while still supplying the body with this essential nutrient. The fundamental building block of any carb is sugar, and those sugars are most commonly broken down into monosaccharides like glucose and fructose, disaccharides like sucrose and lactose and polysaccharides like maltodextrin and cellulose. Your monosaccharides and polysaccharides are the primary sources of energy in your body. Disaccharides get converted into monosaccharides, but this takes the right digestive enzymes and a bit of work.

So how does any of this relate to glycogen?

Your body uses carbs as a source of glucose which it then converts into glycogen and stores in your muscles and liver for when it is needed. Glucose levels in the blood must also be maintained for proper function of your mind and red blood cells, around 130 grams a day to be precise, glucose not carbs. Insulin regulates the levels of glucose in the blood, and this is directly affected by how much sugar and carbs you ingest. Athletes who utilize carb loading for its primary benefits need to check with their doctor first and may need to put together a plan with a dietician. At the least, be sure you do not have any blood sugar issues. Your glycemic response is unique to you and should be evaluated before plowing through carbohydrates.

Another component found in healthy carbs is fiber. Fiber works to build bulk, stimulate the intestines and clean out the digestive tract. All of this is great for the gut but terrible for race day! All the dietary rules you typically follow around carbs need to be forgotten when choosing to carb load. You don’t want fiber rich foods, too many complex carbs or difficult to digest whole grains or legumes. You’re looking for increased energy with rapid digestion, so you want carbs that digest quickly and enter the bloodstream for rapidly available energy. This means indulgences that are typically off the menu.

Consider a bagel with bananas and dates, yogurt with fresh fruits, unsweetened granola with cold milk and yes, you can even enjoy pre-competition pasta. You don’t eat like this all the time, so be ready for some digestive observations. Any food or food combos that cause bloating, gas, distension or bowel irregularities should be cut from your carbo load. These are foods that will slow you down even if others swear by them. You have to eat what’s right for your body. You want to feel full but not choose foods that cause you to overeat for satiation. Test out meals weeks, even months before your event, game or marathon. It’s imperative that you know your stomach, digestive timing and elimination reactions.

Runners in particular and some marathon swimmers already struggle with their guts. High-energy sports and training redirects blood flow at times up to 80% from your internal organs, i.e. G.I. tract, to send it where it’s needed most, muscles and skin. This is what gives so many marathon athletes loose bowels and increased gas. If your intestines are already under increased stress, the last thing you want to do is make things more difficult down there, or you may be spending quality race time in the porta potties. Avoid dense foods and be aware of your own digestive timing. If you don’t think your body will expel it before the big event, don’t eat it! As the day and time get closer, opt for simple carbs and sugars.

There are two key misconceptions to carb loading. The first is that you only need to do it the day before. The second is that you continue training while loading. Neither is true.

Here’s the catch: you use it, you lose it. This means that you have to account for the carbohydrates that your body is using up during your training prior to the event.

If you only carb load the night before, you are setting yourself up for digestive distress and most likely will not achieve your goal. The thing with glycogen storage is that it is much like a tank of gas without a fuel gauge. You fill it up until the pump clicks which is not the max that your car will hold, but it’s as full as you need it to be. Then you run basic errands during the week and each trip uses a little more gas. You know your car pretty well, so you have an idea of how far you can go before you need to fill it up again. If you fill it to max every day and then keep using it for errands, it will keep using gas. This is what you need to know about your body as well.

If you load up on carbs the night before, you’re only filling up what has been lost during your trainings and not creating a surplus in your muscles. You need to begin carbo loading four days to a full week before your endurance event, and two to three days before you need to begin to rest. Consider this time as training your muscles to hold increased glycogen. You want to keep those higher levels which means minimizing your expenditure.

Beware that you will gain weight! But don’t get stressed as you are not putting on mass and the additional pounds should be off the day after your endurance activity. Though you will be choosing high sugar content foods, you will be avoiding high fat foods. Carbohydrate loading will increase glycogen and water content in the muscles resulting in a three to four pound increase in weight, but it is not dead weight and will not slow you down. It will gradually decrease during your activity.

Carb loading done right: increase simple carbs and reduce your activity and training three to four days before your race or game to enhance muscle stores of glycogen.

So just how many carbs should you be eating? Well that is to be determined by your body, your total calorie intake and the actual sport you play. Start around nine grams of carbs per kilo of body weight or four grams per pound and adjust it to meet your body’s needs. Break down your calorie intake into breakfast, snack, lunch, snack, dinner and snack, and do not be afraid to add in seemingly unhealthy foods. This does not mean they are actually unhealthy. Juicing is an excellent option to get whole nutrition with less fiber. Add all-natural jams to your toast, blueberries and maple syrup to your whole wheat pancakes and sandwiches and starches back to the menu. Add in starches. Potatoes mashed with garlic and a bit of olive oil or a rice medley under a filet of salmon are glucose building and healthy.

Be very careful with breakfast the day of the event. You may do better with juices and smoothies. Add a quarter cup of organic fruit juice like orange, grape or apple to your water bottle to keep a constant influx of fresh glucose during the race or game. If your stomach can handle it, opt for light snacks up to the event itself.

There are numerous sample menus and recipe ideas online for proper carb loading, but only you can decide what is right for your body. You may want to talk to your coach or find a sport’s nutritionist to help you smooth out the details, give you fresh ideas and assist with any specific dietary complications. It’s also worth noting that building up your glycogen stores may be completely unnecessary in your body. Take some time to note your performance before, during and after dietary changes. A carb loading diet is the answer for many people but not all. Ask fellow athletes their experiences and seek out the advice of others who have experimented with their diets to get an idea of what to look for, and most importantly, remember to listen to your body in every decision you make.