Originally Posted by digibud

My take on this is the OP's symptoms are classic panic attack symptoms. Hits hard seemingly out of the blue, heart racing, feeling week and if you don't/can't lie down and relax immediately you'll find yourself getting sick. Hyperventalating isn't uncommon and a serious panic attack can be perceived as a heart attack. Did you at any point feel like this was a heart attack? THAT would almost be a clincher, particularly with the "feel fine in 10 min" thing. Panic attacks can go as quickly as they came, sometimes leaving the person feeling fine or possibly tired and a bit weak.
I'll further postulate that it has little or nothing to do with food/hydration. It was a 40 min ride for gosh sakes. NOTHING you eat (other than pure sugar) is going to be digested in that 40 min. If you get a decent breakfast in an hour before you go you don't even need to eat during the ride. No energy will be gained from the banana eaten during the 40 min ride. But also, no NEED for anything to be eaten in a 40min ride. If you're riding hard you probably will want to drink some water but even if you ride hard for 40 min and drink nothing the worst that happens is you are really, really thirsty. (assuming you weren't dehydrated to start) For most people, even those riding reasonably hard, not drinking for such a short period isn't going to have any serious effect. It might the NEXT 40min...
It is much more likely for a person to drink too MUCH water. The only deaths (I THINK this is true...) on the NY Marathon have been due to drinking too much water. None from dehydration.
You can burn 60grams of carbs an hour. maybe 80 in some instances depending on the types of sugars. People that consume 300 grams of food each hour often end up with stomach aches, gas, discomfort. I would again say that in 40min you are pretty much totally getting your energy from stored up fuel.
As to bonking....bonking happens when you have entirely depleted your glycogen reserves and your blood sugar level is dangerously low and you are probably having a hard time thinking, standing, moving. That's bad bonking. Truly NO energy left. People often use the term lightly when they just get really tired and decide to stop but when you bonk bad you are done and will have to stop for at least some rest, at the minimum.
So my advice is to have a good breakfast as early as you can prior to leaving for your ride, be well hydrated and dress so you don't overheat. The dressing thing takes time to figure out. I keep a record of exactly what clothing layers work at a variety of temps.
My wife says "tell him to suck it up". grin
I'll bet that panic attack (if I'm right...) is a one time thing due to the sheer discomfort and foreign nature of the ride but just keep it up. Day after day you'll get stronger and stronger and soon enough 5mi will be nothing and if you want, you'll soon be doing 20, 30 and more miles. Good luck.

Originally Posted by Carbonfiberboy

It feels fine until it doesn't, so I try to make a habit of eating.

Originally Posted by Ramona_W

This could apply to so many different aspects of life that, with your permission, I'd like to file it away for future reference/use.