A few weeks ago I was warming up for a 5K time trial. It was a straight out-and-back course, and during the warm-up I wanted to see what the maximum speeds were that I could expect to hold. On the out leg, which was into a pretty strong headwind, 21 mph seemed hard but sustainable, while 22 was too hard, so I planned to try to keep it between 21 and 22 during the race. On the way back, with the wind, 26 mph seemed like a worthy goal.
During the race, on the out-leg I look down and see that I'm holding 23 mph and higher. And coming back in I'm doing 27-29. I wouldn't have believed that possible, based on my warmup testing.
So now that I know what adrenalin can do, I'm thinking of putting a time-bomb on my bike for time trials, that will go off unless I finish the race under some preset time. If it works, I plan to market it: "Better than 'Roids - It's the Bomb!" If it doesn't work, I'll be a sore loser.