I figured with all the nutrition questions and advice going around I'd share my commute story from last night as it was a very valuable lesson learned. I was hungry yesterday when it was time for my nightly commute home. I ate a Luna Bar about 1/2 hour before time to go home but I was still hungry. I'm thinking no biggie, I'm going home after all, it's only 6 miles (ok....with a 400' elevation gain but whos counting) and it's not like I"m going to "race" home so what's the big deal. I had not a clue what "bonking" was although I knew it was somehow related to long rides and not enough nutrients. So...this was a short ride and I'd eaten a Luna Bar - doesn't apply to me right?.......Wrong
About 2 miles from home is a very short, very steep hill that tops out at the trailhead and it involves a short intense climb and then a fast stop for the traffic. I reached the top of the hill and knew I was in trouble. I was shaking, breaking out in a clammy sweat and my brain was screaming "UNCLIP, UNCLIP" but the feet just were not getting the message. I'm pretty sure I looked like the little tricycle guy from the old Laugh-In show, I just fell. Both feet still clipped, hands still on the flats. I was so out of it I didn't even check the bike when I got up. I got back on it and started riding like some crazy drunk until the brain finally got thru that I had another Luna Bar in my pack, stop and eat it NOW!! The second bar got me home where I did some major protein loading with complex and simple carbs to start getting my sugar back in balance.
Long story short (too late), bonking is a blood sugar drop and it doesn't matter how far you're riding, if your body doesn't have it, you can't use it.
I have found what was causing the sugar imbalance and have removed it from my diet but it could take another 24 hrs to bring my sugar back in balance, and a while longer for the owies from the fall! I'm fine, some scrapes and bruises and Allez is just fine - he had me to cushion his fall lucky dog!

Lesson learned: if I'm hungry, eat until I"m not or have someone take me home coz to ride like that was just stupid and dangerous.