Carbo Loading

Carbohydrate loading is a technique used to maximize glycogen stores for long endurance competitions. Without careful planning, after a couple hours of strenuous activity, glucose stores can deplete causing dysfunction with the nervous system and will make continued exertion almost impossible. Let’s avoid this, yeah?

Thousands of studies have been conducted on this topic since carbohydrates were identified as the most efficient energy source over 80 years ago. Today the discovery goes on and on; does carbohydrate loading solely prevent fatigue? Can it actually improve performance? What is the best type: food, liquid, supplement? Does the timing of intake make a difference, etc. It’s overwhelming right now the piles of books, journals, and pages I have found just on this topic. For your sake, and my sanity, I am going to keep this basic.

I will begin by saying, that carbohydrate loading is pretty much unnecessary for athletes participating in events lasting less than 90 minutes. I mean, the orange slices at the soccer games, and spaghetti dinners the night before track meets are great, but the increasing load of carbohydrate intake days before an event and doubling your grams/kg/day amount is a little overboard.

So how does carbohydrate loading work? The key is to consume substantial amounts of carbohydrates a few days prior to the event and at the same time decrease the duration and intensity of training to assure plenty of endogenous glycogen stores. This sort of tricks your muscles into storing more glycogen and can possibly double muscle glycogen concentrations! Here is a good basic “how-to” chart.

Before the Event Training Intensity Training Duration  Dietary Carbohydrate
6 days Moderate (70% VO2 max)      90 min Normal (5g/kg body wt)
4-5 days Moderate      40 min Normal
2-3 days Moderate      20 min High-Carb (10g/kg body wt)
1 day Rest        — High-Carb

Some people (those who do not struggle with reactive hypoglycemia) do well to have a little bit of carbohydrates about 90 minutes before an event. Also, it is important to eat around 60 grams of carbohydrates immediately following activity to replete glycogen stores. And carbohydrate ingested during prolonged activity can help maintain blood glucose levels and even reduce the psychological perception of effort. Cool huh? This is when Gatorades and sports gu’s come in handy.

Those of you who exercise regularly and intensely, but do not fall under the endurance category, would do well to have a higher carbohydrate diet all around. 5-8 grams/kg/day is a good target for ya’ll.

SO…for some perspective, the following snack ideas provide around 60 grams of carbohydrates:

  • 16 oz sports drink and a small bagel
  • 2 pieces of toast with jelly
  • 8 oz pineapple juice and a granola bar
  • 1 large sweet potato w/ juice or sports drink
  • Other good concentrated carbohydrate foods include dried fruits, nectars, and athletic gu’s.

Carbs and Exercise

Alright all you activity goers, let’s talk carbohydrates and how to select them. Remember the tid bit here about how carbs store as glycogen in the liver to be used during activity? Keep that in mind during this discussion.

Our carbohydrate needs is one the most controversial topics in the nutrition,dieters, and exercise world. This is because there is no official requirement for this nutrient class. There is no such thing as a carbohydrate deficiency (there is such thing – and seen too much in third world countries – fat and protein deficiencies) because there are no essential carbohydrates. Carbohydrates can be produced in a lot of different ways in our bodies if necessary, and there lies the problem. How can we set a minimum or maximum requirement?

Dieters always want to cut out carbohydrates and fill up on protein, but those who follow high-protein, low-carbohydrate diets will find themselves pretty fatigued half way through their exercise routine. But wait, can’t fat be converted to glucose to be used for energy during work outs over 20 minutes? Yes, but this process is slow. If your body is already low on fuel (aka glucose) you are going to feel totally drained before the fat converting magic even happens. If you don’t feel energized you can’t finish your work out. If you can’t finish your work out, you won’t burn calories, If you don’t burn calories your diet really isn’t going to help much in the end. See the problem?

But on the flip side, sometimes we go over board with the whole carbohydrate and exercise thing. The best example I can think of is 5k races. So a little over three miles, this race can easily be done in 30 minutes if you jog. Yet, we have a station half way through passing out Gatorade and orange slices. And then when we complete the race they hand out bagels and chocolate chip cookies. Those who organized the race must know a thing or two about running and nutrition, right? So I need to fill up with everything the 15-year-old volunteers throw at me, right? Wrong. The volunteers aren’t handing it to you because it is the best nutritional choice for you, but rather it was donated and the people have grown to expect and demand it! The truth, you don’t need to carbo load for a work out like that. Whatever stores you have from dinner the night before should be sufficient, and calories still count! A person burns around 300 calories during a 5k race, and one cinnamon sugar bagel and a swig of Gatorade will cost you around 600. Owch.There goes all your hard work to complete that race!

So where is the balance? Remember this chart I told you I would come back to? Find where you think your calorie range is by multiplying your weight in kg (divide your pounds by 2.2) by 25-30. Use 25 if you are sedentary or trying to lose weight, 30 if you are extremely physical or trying to gain weight.

ex- a 120 lb female who jogs 45 minutes a day

120 lbs / 2.2 = 54

27   (medium activity level for weight maintenance)

54 x 27 = 1458 kcals/ day

Once you find your calorie level, look at how many calories should be from carbohydrates when using the 50-25-25 rule. So our example 120 lb female, let’s call her Rapunzel. would need around 700-725 calories of carbs or 175 grams (4 calories per gram of carbohydrate) per day. So what choices does she have and what does that mean in real life? Rapunzel doesn’t count calories…

The best carbohydrates you could select are those that are fiber-rich and/or have a high water content. Eating these types of foods will slow your digestion, help you feel full, and give you lasting energy during your work outs. These complex carbs would be fruits, vegetables, and whole grains. Obvi.  A lot of people get this notion that a calorie is a calorie, a carb is a carb, I’m going to have a danish pastry before my runs and fill up on donuts the rest of the day. Well first of all, people really tend to overestimate how much they actually burn off, and secondly, even if you stay in your calorie allotment, you’re body isn’t going to sustain its glycogen stores as well with these simple sugars. So prepare yourself to consistently consume good complex carbohydrates if you want to slim down or perform at your best.

Now the good part. What to pick. Print this out and put it on your refrigerator, please.

Best Carbohydrates

Fruits (60 calories per serving)

Apple, orange, pear, nectarine: 1 small (tennis ball size)

Peach or plum: 1 medium (fist size)

Banana – 1 small (5-inch) –mostly we eat bananas that count as two serving sizes…

Kiwi: 1 whole

Grapefruit- 1/2 of whole fruit

Grapes- 1 cup or 17 if you want to be exact

Cherries- 12 to be exact

Berries – 1 cup

Mango: 1/2 small

Tangerines or clementines : 2

Pineapple: 3/4 cup diced (can you dice pineapple? you know what I mean…)

Canned fruits (no syrups added): 1/2 cup

Vegetables (25 calories per serving)

Raw vegetables : 1 cup

Cooked vegetables : 1/2 cup (carrots, broccoli, cauliflower, cabbaef, green beans, eggplant, onions, etc)

Green pepper: 1 whole

Asparagus: 7 spears cooked/ 14 spears raw (please tell me if you eat these raw!)

Leafy greens: like 5 cups

Carbohydrates to Choose with Caution (aka watch portions)

High-starch vegetables (80 calories per serving)

Beans(black, lima, kidney, pinto, etc): 1/3 cup

Corn: 1/2 cup

Corn on the cob: 1 medium ear

Peas and lentils: 1/2 cup

Baked potato or sweet potato: 1 small (tennis ball size, we mostly eat double this…)

Pasta/rice ( 80 calories, choose less if you like)

Couscous: 1/3 cup

Rice (brown or white) : 1/3 cup

Quinoa : 1/4 cup

Noodles (whole wheat or white): 1/2 cup

Bulgur: 1/2 cup

Breads/Cereals/ Crackers (80 calories per serving)

100% whole wheat bread : one slice (actually around 100 cals, so you must read labels!)

Tortilla (wheat or white): 1-6″

Mini pita bread (5″): 1

Bagel: 1/4

The rest in this category can be found on labels, please read them!!!

I challenge you to keep track of your carbs for just one day. Notice portions, refer to this chart, and see how well you did. This experiment can at least give you an idea of where you could improve, or maybe you will be pleasantly surprised with yourself. If you have specifics on other not-listed items, feel free to ask me!

Next up, to carb load or not to carb load?


I have been reading this great book and I have been pleasantly surprised that I agree with the nutrition advice. One concept I would like to share today is the 50-25-25 rule.

This rule says that 50% of your daily calories should come from carbohydrates, 25% of your daily calories should come from protein, and the last 25% of your calories should come from fat. According to Madelyn Fernstrom, PhD, CNS, this is good advice for runners (and may I add most athletes). This theory of calculating our daily allotment into three groups rather than individual and specific calories will lighten your dieting burden loads.

This rule does 4 important things:

  1. It allows you to incorporate moderate amounts of carbohydrate int your daily diet
  2. It gives you sources and options for foods that give quick energy for physical activity
  3. It provides the right balance of protein and fat to give you continued energy
  4. It allows you to remain content and satisfied throughout the day while still losing weight and having enough energy

As I continue to blog and break down the three macronutrients I will give you specifics and suggestions and this 50-25-25 ratio will make more sense. This is a teaser post I guess you could say.

I also want to share this chart. This breaks down calorie portions. Again, consider your personal calorie range and keep this in mind for the posts to come!

50-25-25 Calorie Distrubution

 Daily Calories                   Carbohydrate kCals         Protein kCals             Fat kCals

































Exercise Physiology 101

Nerd alert. This post is going to be a little scientific, so lets get physical (as in lets discuss physiology). And if it’s too much, just skip ahead to the “Take Home Messages” at the end to get a very fast run down of everything that I will now take 10 paragraphs to explain…

Nutrition and physical activity go hand in hand because activity demands carbohydrates and fat as fuel, protein to build and maintain muscle, and vitamins and minerals to support energy metabolism and tissue building. And of course you need water to help distribute fuels and hydrate.

Two terms I would like to share with you today are ATP and CP.

ATP: Stands for adenosine triphosphate. This is a form of energy that is available for immediate use in the body. All energy- yielding nutrients (carbohydrates, protein, and fat) can enter metabolic pathways to make ATP.  Small amounts of ATP are stored in tissues at all times, even during rest, and in the muscles ATP provides the chemical driving force for contraction (think about how often you are moving your muscles, like always). When an ATP molecule is split, it’s energy is released and the muscle cells channel the energy into mechanical movement or as heat.

CP: Stands for creatine phosphate. CP is made from creatine, a compound found in muscles. This compound can split anaerobically (without oxygen) to release a phosphate and replenish ATP supplies. What this means to you is, this is the short term fuel for our bodies. When we participate in high intense boughts of exercise (like a sprint 100-meter dash) our bodies can use CP to produce energy quick and without oxygen. This energy source however usually last for only a matter of seconds. It also acts as a replenishment for ATP. When your muscles are resting, ATP feeds energy back to CP by giving up one of its phosphate groups to creatine. Therefore, CP is produced during rest by reversing the process that occurs during muscular activity.

Are you sufficiently confused already?

Well think of this. ATP and CP are stored in small amounts in your body. If you tried exercising with zero fuel (aka food, energy, calories, however you want to say it) how long do you think your activity would last? Not so long. So this is why it is important to have adequate food and energy stores to perform well. Carbohydrates, fats, and proteins store in our bodies to be utilized during activity.

After you consume carbohydrates, your body stores whatever is not needed right away in a storage form called glycogen. Glycogen is saved or stored in your liver. Your body can then go shopping for energy when you need it. Like when you haven’t eaten for 4 or 5 hours and your body starts needing back up energy, or to sustain ATP production during exercise.

How much carbohydrate a person eats influences how much glycogen is stored. When a person is exercising, glycogen will last depending not only on diet, but also on the intensity of the activity. For example, moderate activities like jogging when breathing is steady and easy, use glycogen stores slowly. But during intense activities, like sprints or races where it may be difficult to “catch your breath, ” glycogen is used up real quick. Usually, a person’s glycogen stores are used as fuel for the first 20 minutes of exercise. After 20 minutes of exercise a person who continues exercising moderately begins to use less and less glycogen and more an more fat for fuel. Have you heard that you don’t start burning fat until 20 minutes into a work out before? Well its absolutely true.

During the first few minutes of utilizing fat as a fuel, your body is calling on free fatty acids circulating in the blood stream. After blood levels fall, the body calls on a hormone epinephrine to signal fat cells to break down and release their stores of triglycerides. Therefore, sustained, moderate activity uses body fat stores as it’s major fuel. So get a good 45 minute to hour work out if you really want to see that fat melt off ya! But in this case, the intensity of the work out also affects the utilization of fat stores, As the intensity of activity increases, fat makes less and less of a contribution to the fuel mixture. A lot of oxygen is needed to break down fat for energy , and if a person is breathing easily during activity, the muscles are getting all the oxygen they need and are able to use more fat. So moral of story, if you want to burn fat, look for activities that require a steady but longer duration. Moderate long distance runs, swimming, and bike rides are good activities. Or any sort of aerobic class or activity that keeps the heart rate pretty moderate.

The longer you train or stick to an activity, the body gets better at permitting the body to draw more heavily on fat for fuel. Also the heart and lungs become stronger and better able to deliver oxygen to muscles at high activity intensities. This explains why sometimes it may take a few months of training and consistent exercising to get your body to start burning fat and to see results. So don’t give up!

Protein is actually not a a major fuel for physical activity. Nonetheless, physically active people need an ample amount of protein in their diets to build muscle and lean tissue. Eating carbohydrates before exercise is needed to prepare your glycogen stores for utilization, but carbohydrate intake coupled with protein after an activity is important to replenish those lost glycogen stores and promote muscles synthesis. Don’t worry, I will dedicate a whole blog to amounts and eating guidelines, but for now it is important to say that it is important to have protein to rebuild muscles.

Only ten percent of the total fuel used during exercise comes from proteins and amino acids, but during activity, muscles turnover amino acids stores much quicker, and protein must be provided at the end of the work out to make sure you have bigger muscles in the end and not wasting ones. Longer work outs, after all the glycogen and fat stores are used, then rely on protein stores. So endurance athletes require the most protein during a work out than any other athlete, even body builders who actually use less protein during an activity. Weird huh?

Quick take home messages:

  • ATP and CP are energy sources in your body. ATP is made aerobically and requires carbohydrates, fat, and protein to produce ample amounts. CP is used to replensih ATP and for short intense energy and does not require oxygen to be utilized.
  • Carbohydrates are your body’s first means to get energy. When you eat carbohydrates, excess amounts are stored as glycogen in your liver to be used for later use and during work outs.
  • Glycogen stores are usually used for the first 20 minutes of a work out, even quicker if the activity is intense.
  • Fat stores are used after 20 minutes of a work out. Longer moderate activities require the use of fat fuels. The longer you train and the greater your lung’s abilities to provide sufficient oxygen, your body will use fat as a major fuel during activity.
  • Protein is needed for recovery and muscles replenishment and building. Protein is used as fuel source only in long duration activities (sport’s games or long runs).
  • And finally,