While it may seem trivial, it’s very important to understand how your body uses glycogen. Why you’re losing it – and establishing ways to control it – is also key to performing at your peak.
So what exactly are the factors and what can be done to control them?
When it comes to the rate that muscle glycogen is used, your diet plays a big part. In particular, the amount and ratio of your macronutrient intake. That is, how much fat, carbohydrate and protein you eat.
In a study, a group of professional rugby league players were split into two. One group was given a traditional high carb diet in the 36 hours prior to the game. The other group was given a lower carbohydrate diet in the same period. Results showed that the lower carb group experienced a lower drop in glycogen.
The relative carbohydrate and fat content of an individuals’ diet seems to have the most significant impact on glycogen use/sparing during exercise.
A study published by MuscleSound shows how much glycogen use can vary between individuals performing the same exercise. In the study, each participant completed a 75-km cycling time trial.
Participants took, on average, 168 minutes to complete the trial. While muscle glycogen decreased an average of 77.2%, some individuals lost over 90%, while others only lost around 10-20%.
Losing too much during an event can cause fatigue. Once your levels really dip, you can say goodbye to powering through that workout or race.
Therefore, low intensity training is the key. This type of training helps to build the mitochondrial mass in muscles. This is the body’s key machinery used for burning fat. Racking up repeated long and slow kilometres is a proven way to build fat burning capacity, which in turn offsets glycogen use during exercise.