I get terriable muscle shakes whenever I ride. Doesn't matter if it's my AM commute (about a mile) or my long weekend ride (about 30). I get off the bike and can barely walk. Yeah, the commute is a fairly hilly sprint along with dodging traffic at an onramp, but it's sort of getting ridiculous. I'm not tired, hungry or fatigued. I am nauseous and have difficulty controlling my muscles (they just don't get the 'walk guys' message!)

I've got a family history of diabetes but I don't have the disease. I'm a fairly small at 5'4; 5'5 on a good day and about 120lbs. I'm also fairly built and female, which might have something to do with it? I think my body fat percentage is something around 11%, but I could be very incorrect if that sounds insanely low. A roadie friend of mine thinks it might be a glycogen/hypoglycemia problem. The thing is, I'm not on low-carb, I eat a fair amount of sugars and carbs and always take in at least some sort of carb-y thing before riding, either something like a slice of toast or a cup of orange juice. I can't keep anything down immediately afterwords besides watered down juice or water.

any suggestions? ideas on what it might be?

I think you should see a doctor on this one.

Find a sports medicine doctor. The symptoms you describe would make sense after super hard efforts or if you were on a severe calorie and carb restricted diet. Since you're not doing any ot that and you still have the problem, it sounds deeper and should be looked at medically.

i have a friend who rides and is diabetic...the symtoms you descrided are identicle to what he experience after a short ride...he gets shaky and has to sit down for a while....sounds like your getting midly hypoglycemic..

i have diabetes in my family (my father) and i sometimes feel just like that on rare occasions even after food...i dont have diabetes as such but perhaps there is a trace, i havent seen a doctor because it so infrequenst with me but i think like the other guys said...you should..