I’ll take a pre emptive stab at this…
In a nutshell, muscle glycogen is used only for exercise and only for that muscle. It is a large “reserve” for intense physical activity. Liver glycogen is used by the brain/nervous system. Once the muscle glycogen is there, it’s there for good until it is needed for muscular action.
It is the glycogen in the liver that can be a harbinger of doom.
We all know that when you eat a high carb meal blood glucose rises and insulin is released. Insulin acts on several enzymes with one result being the synthesis of glycogen. Of course glycogen has a number of possible destinatioins: storage in the liver, storage in the muscle, use as fuel, storage as fat. It’s in the liver that this glucose derived from liver glycogen runs into problems.
There’s only so much storage in the liver, when that’s full it will head to the muscles, when that is full it will be converted into fat.
Enter fructose…
Fructose is not readily stored as muscle glycogen. It is not digested like other sugars/starches. In fact, if it’s not stored as liver glycogen it will be stored as fat. That’s why you must be careful when consuming fructose. Morning consumption is fine because your body uses up much of its liver glycogen at night for fuel. The rest of the day depends on your diet.
If you’re on a low carb diet then it’s likely your liver glycogen will be low pre/post workout. So consuming some fruit during this time should be fine…again, individual diet will determine this. I would let your energy level be a good measure. You ‘hit the wall’ when your liver glycogen stores fall. You’re on a low carb, low calorie cutting diet and you begin to notice falling energy levels? That’s your falling liver glycogen. At that time it should be ok to eat fruit.
Your body will refill liver glycogen before it worries about muscle glycogen because it needs liver glycogen for the brain/nervous system. So, if your goal then is to refill muscle glycogen as quick as possible then you should first refill liver glycogen first.
This is where fructose comes in. As stated above fructose is digested differently and just doesn’t get stored as glycogen in the muscle, only in the liver, so consume fruit to restore liver glycogen in the morning then complex carbs the rest of the day.
Anyway, that’s my 2 cents…well more like 2 dollars…