Glycogen Loading: Good or Bad?

Even Though It’s Disproved, Glycogen Loading is Still King

In the late 1960’s, Swedish researchers developed a new dietary protocol to increase performance.

It went like this: cut way down on carbohydrates (breads, sweets, fruits, and some vegetables) and eat nothing but protein and fat for three days.

Then, on days 4, 5, and 6 (game day is day 7), load up on carbohydrates. In this way endurance performance would increase.

So glycogen (or carbohydrate) loading became the dietary king and still rules today. The trouble is that many people missed the point: carbo loading only works for events (or competition) where the athlete must perform for long periods of at least 90 minutes.

For other athletes, and that’s most sports (including football), the time of activity is short and muscle and liver stores of glycogen are not limiting factors.

Glycogen is the storage form of blood sugar or glucose. Your liver holds about 3/4 of a pound and muscles about 1/4 of a pound. The primary purpose of liver glycogen is to supply glucose for the blood. As glucose enters the muscles, brain, and other organs, the blood sugar levels drop and the liver provides additional amounts.

The Primary Fuel of the Body is Fat: at Rest 90% of Your Energy Comes from Fat

Most scientists do not understand this fact. With the assumed implication of fat to obesity and heart disease, very few scientists have researched the “fat as fuel” studies.

As exercise intensity increases, the body uses a higher percentage of carbohydrate to supply the energy for the event. This notion has led to an emphasis on carbohydrate as the primary fuel for exercise.

The percentage of total calories consumed each day has risen from about 40-45% years ago up to as high as 70-80% today. Some of the popular sports performance drinks and sports bars are 70-100% carbohydrate.

The increased use of carbohydrate has led to a decrease in protein intake. This shift to low protein-high carbohydrate has led to changes in body composition: less muscle and more fat.

Conventional Wisdom has it the Other Way Round: Most Athletes Believe They Need Lots of Carbohydrate to Build Muscle Tissue. Wrong!

In a study of bodybuilders, one group of athletes ate about 270 grams of protein per day including eating up to 82 eggs per week. Compared with the low protein group, the high protein group had 7 pounds more muscle and 4 pounds less fat on their bodies.

The high protein group also ate a diet higher in saturated animal fat. Contrary to popular belief, the blood fat levels of these athletes was excellent. Their risk factors for heart disease were also very low.

The movement to higher carbohydrate diets is of no value to strength/power athletes. A typical professional football game is about 9-13 minutes of physical activity.

A recent study showed that this amount of playing time hardly reduced muscle glycogen levels. Further, the high carbohydrate diet may actually decrease performance in several ways: 1) decrease energy, 2) decrease muscle mass, and 3) decrease strength.

In short, high protein-moderate carbohydrate diets will enhance athletic performance in strength/power athletes.

My recommendation is to reduce carbohydrate consumption to less than 25% of total calories to gain optimum athletic performance.