Sorry, should have been more clear. Glycogen and lactate are more predominantly consumed by working muscle than is blood glucose. Unlike other tissue that uses glucose more readily, the rate of blood glucose consumption by muscle tissue is relatively limited and I'm not sure that a greater capillary density would increase muscle uptake of glucose and spare glycogen.

This is stretching my memory, but according to the 'glucose paradox', glucose released into the blood from dietary carbs is used by muscle tissue to either synthesize glycogen or produce lactate. Blood carries the unused lactate back to the liver to produce either glucose or glycogen. Unlike O2 uptake, I don't know that glucose uptake is limited by Q to the muscle. That's all I was trying to say.

You stated, "Since the depleted glycogen stores can no longer contribute to the maintenance of blood sugar levels, that concentration starts to decline. Reduction in the concentration of blood sugar = trouble.. "

I think that's backwards. Muscle glycogen doesn't contribute to blood sugar levels. Blood glucose is used to form (directly or indirectly) liver and muscle glycogen.

But that's just a 'layman's' version.