I have learned something from a couple of my rides this past week. I tried eating prior to my ride to have a little more energy as I was going to do a 60 mile ride. I hadn't done anything that long for at least 10 years. I ate a bowl of shredded wheat in Silk with a banana. During the first hour and a half of my ride I couldn't give any effort without my heart rate going way high. I putted along a 14 mph on the flats and my heart rate was 145. After the hour and a half were up, I rode a little better and my heart rate went down into the 130 range but I was still only going 15-16 mph (still on level ground). After another hour, I finally was able to get up to speed and cruised along at 18 mph and my heart rate stayed about 130. After doing that for awhile I started getting tired and so I stopped and ate an Energy Bar and tried to ride again and felt like my legs were absolutely out of gas. I did make the ride but felt like crap most of the time.
I ate pasta the night before and slept fairly well. What gives? After the ride, I also had very little appetite.
Not sure, that's strange... they say digestion diverts some of the blood flow... but that is very dramatic.
I'd attribute it to normal cycles the body goes through... you can be on a high for so long and then your body grabs its recovery without warning, and just doesn't cooperate.
If you have upped the intensity in general, it may have finally showed up this one ride...
I was training for a halfironman and 4 weeks from race day I just went to blah energy levels for 2 weeks!!! I couldn't get enough sleep, and I couldn't get a good enough workout in... after 2 weeks I was good again, and hopped back out there ready for race day, but overtraining hits your body first, and you realize what happened later...
Then again, everyone has a bad day every once in a while!