The liver can turn either fructose or glucose into glycogen while muscle tissue can ONLY store glucose as glycogen.
The liver is capable of converting some fructose to glucose, but not much at one time and is only done as-needed based on the demands placed on the body.
Why is this important? Well, no matter how much fructose you consume it won’t be significantly contributing to replenishing muscle glycogen. It will mostly be stored as glycogen in the liver. That is the determining factor as to whether fructose is “good” or “bad” to consume. It depends on how full your liver glycogen stores are.
The liver has a very limited storage capacity and once it is full, the remaining fructose has to be used some other way. This is when the fructose will go down a different pathway and can contribute to inflammation, insulin resistance, and be stored as body fat. Only a very small percentage may be converted to glucose, and that is only if the body has a demand for it.
For example, if you’re having a meal with a lot of both fructose and glucose, there isn’t much reason for your liver to convert fructose into MORE glucose, since there is already some available. This is why we recommend limiting fructose in a carb loading meal.
When we look at performance and recovery, muscle glycogen is the most important to replenish. Glycogen is used locally, so restoring glycogen after each training session will be essential to facilitate recovery and output for the next time you train those particular body parts.