I signed up for a 32-mile ride, but after 20 miles, I felt like I was pedaling in cement; I was in the lowest gear but my legs were heavy and I could only go very slowly. After checking the threads on bonking, I don't believe that I bonked, but it such a strange feeling. After about five minutes of rest and some Cytomax, I started pedaling, only to discover that pedaling was now a breeze and took almost no effort at all. What do you think happened? I've not experienced this before, even after cycling many, many miles over many years. Thanks in advance!