Day two of the multi-hour weekends of the final two weeks of winter endurance training: another 4 hours on the trainer. This time it was incredibly different. On a wim, rather than doing my planned 5 hour back-road country ride, I hopped on the trainer this morning after 4 hours on the trainer yesterday. Hurt and tired, I had this gut feeling I wanted to ride the trainer again. And so I did. At the three hour marker, I wondered how much more I could tolerate. Digging just a bit deeper, I endured another hour. It was a real struggle to get through the full four hours and many, many times I was near exhaustion and dead-tired; but when I finished, something magical happened that I never experienced before -- exercise euphoria. I went into this state of total calm...total relaxation... and total peace and comfort. There were no aches or pains or tiredness. Just complete tranquility. For a couple hours afterwards, I was high - totally off earth and de-stressed. I don't think anything could have brought me down. Low and behold, the euphoria I felt IS a real condition complete with scientific studies to prove it. From Fit Day: This effect is especially pronounced during prolonged periods of strenuous exercise. Massive amounts of endorphins are released to help you mask any pain and help you push past your normal threshold. The euphoria comes from runner's high and release of endorphins. From a good article on Runners high in the NY Times: The runner’s-high hypothesis proposed that there were real biochemical effects of exercise on the brain. Chemicals were released that could change an athlete’s mood, and those chemicals were endorphins, the brain’s naturally occurring opiates. Running was not the only way to get the feeling; it could also occur with most intense or endurance exercise. I'm sure some of you had gotten into this state before, but this is my first and what a feeling it is. If only we could harness that whenever we wanted. Wow. I'll just bet the TSE will be another euphoric experience. Pushing beyond the norm seems to bring it on, and we'll be breaking through thresholds we've never experienced before.