Re-fueling while cycling made all the difference

Am a hobby-cyclist. I wouldn't even use the word amateur, as it already conveys a sense of aspiration to professionalism that I do not have. I specifically reject the idea that you need to follow any kind of 'norm' or 'trend' by using specific bikes, wearing specific cloths or be in a specific shape to do cycling. I think, all you need is a bike. That doesn't mean that I'm without goals or aspiration in general. I do like to go fast on a bike. And I'd really like to be able to go far, too. Ideally both at the same time. I'm not denying basic physics (I have a lightweight(-ish) bike with slim(-ish) tires and reduce my air resistance by hunkering down on aerobars.) But seemingly I was in denial about bio-chemistry. My attempts at longer rides so far hit a wall at about 50km. Not literally of course, but after I returned home, the effects were not much less unpleasant. Nausea, dizziness, stomach cramps, almost blacking out in addition to the inevitable hurting muscles. This lasted for…