I just did my first ever 40k TT. It wasn't an official race, just me on an isolated trail seeing how I might do, so I decided to take the plush M5 rather than the faster but much less forgiving M1.
The experience only confirmed what I've always known, but I'm glad I did it. The first few miles went fine, occasionally reaching a cruising speed of 27 mph. But after mile 5, I experienced a big drop in power output, losing about 1 mph. I thought it might have been caused by a sudden headwind, but a glance at my Garmin removed all doubt; it was definitely a power loss. The only good news for the remainder of the TT was that my fatigue level didn't increase any further, as I feared it might. In the final two miles or so I managed to keep going at ~25 mph without any noticeable increase in lactic acid or running short of oxygen. In fact, I'm now convinced that I could have pushed myself just a tad harder for an extra .5 mph, but didn't realize that until the very end. When I dismounted and tried to walk the bent back to my car, I felt dizzy, a bit nauseous, and my hands were shaking. I became aware of a thumping sound and thought it might be a jogger on the trail behind me, but it was the sound of my own heartbeat.
![Eek! :eek: :eek:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
So, no real surprises here. As has always been the case, it seems I'm just not cut out for any sort of endurance sport. Still, I did well enough to win one KOM on a seven mile segment and narrowly missed wining another one of equal length. That will give me the incentive to try again.