When have athletes having bad performances because they were too "pumped up"?

J.Barringer at nat. Might not have been to "pumped up" but she could have relaxed the first part of that race instead of trying to lead from the start.

El G, Sydney.

alan webb at olympic 2008 trials, 2005 WC

kadevis robinson, also at 2008 trials, told himself itd be "the greatest achievement to qualify for another games with his 2 year old son watching in the stands" bit too much pressure...

adam goucher, 2000 olympics, wasnt even in contention for a medal but kind of pooped out

andrew wheating, junior year of college was running a mile race and wanted to run a 3:55, was getting himself pumped to run that and hyperfocused on the time. ended up only going 3:59, which was still his first sub 4 but not what he originally intended

and ive had my own personal experiences with overhypeing

As a runner myself I definitely appreciate and accept your examples, however, as a teacher I need to present an example that my high school students will better relate to.

I too would be interested in hearing some examples!

well, I have had personal expiriences with this, it's happened a couple times, where I psych myself up to much, and put alot of pressure on myself, I blew a chance to advance to regionals (track) and semi-state (cross), I find that I race best calm and collected, and race to a good time, instead of pyshcing myself up with things like "man you can win this" "you have run with these guys all year you can beat em" stuff like that. It's you against yourself, not the other competitors. These examples may not be as specific as the prior ones, but they are high school examples none the less. Just calm down, be confident, and race smart, and it won't happen. Don't run to place, just run your own race.