EDIT: I totally read the thread title wrong, so this info doesn't really answer your question. In case you were wondering about exercise blood sugar regulation, well, here you go!
-- Biochemistry alert :( --
When on SAD, you are insulin insensitive. Circulating at any given time, especially after insulinogenic meals, is an unusually high concentration of insulin. Insulin leads to glycogen synthesis and uptake of free blood glucose. This is a normal parasympathetic process, a "resting" process. Insulin binds to receptors on most cells of the body that leads to a signal to take in sugar from the blood. Insulin binds to cells in the liver to tell it to form glycogen from the liver for storage.
When on Paleo, you are insulin sensitive. While exercising, glucagon and norepinephrine/noradrenaline are present in much greater quantities than when at rest. These hormones bind liver cells and signal glycogenolysis, a process that digests glycogen into glucose and releases the free glucose into the blood where hungry, worked-out cells can take in the glucose and metabolize it for energy (I'm looking at you, slow-twitch muscle fibers). This is a normal sympathetic process, a "fight or flight" process.
Both insulin and glucagon/norepinephrine bind to different, antagonistic receptors on the same liver cell type. SAD dieting increases base insulin levels relative to glucagon/norepi levels. Paleo dieting reduces base insulin levels relative to glucagon/norepi levels. In the case of SAD, insulin's signal to the liver may be so strong relative to that of glucagon/norepi that the glycogenolysis process that would otherwise feed your hungry muscles is instead being antagonized by the glycogen synthesis signal from insulin. Paleo, on the other hand, prevents this antagonism by attenuating insulin levels and allowing the glucagon/norepi signal to transmit to the liver.
Net effect of SAD: Too strong base insulin signal -> insufficient glycogenolysis -> low active blood sugar -> insufficient sugar supply to muscles and brain -> muscular and mental fatigue
Net effect of Paleo: Relatively weak insulin signal -> proper transduction of glucagon/norepi signal -> glycogenolysis -> increased blood sugar -> sufficient sugar supply to muscles and brain -> maximally efficient muscles and neuromuscular pathways -> bulging muscles -> hot new girlfriend