Most people would expect this to be the value of power output that you could maintain over an entire ride but it isn't. It essentially is the amount of power you can output over only about 20 minutes. So if you're out on a Century or the like you most assuredly cannot put out power like that since you will rapidly become fatigued and your speed will drop off sharply.
I have a pretty good idea of the amount of power I can deliver over the length of a Metric or even a Century and it amazes me to watch groups flying by me (well I am older than dirt now) and then catching them at each rest stop. They overestimate their capacity and run themselves down and then act insulted when I beat them back to the finish while they are falling off of their bikes from exhaustion. Believe me, it isn't because I'm a better rider any more. I just recognize my own limitations.
One of the tricks I've used is to ride the same distance you intend to do a week ahead of your organized ride. This will make you a lot more wary of riding too fast for the distance. Usually though, these people will be in packs and racing each other as if an organized ride was a race.
The last organized ride I did was at the end of 2019 and I caught up with a man on an MTB after the last rest stop. Seeing some broken down old fart next to him he was convinced he could ride with me. So on a course, the end of which was continuous rollers, he gradually slowed down on the top of each rise and would give it everything on the following descent to catch up until he finally blew sky high. That was a bit unfortunate since it was only about 2 miles more to the finish line. Out of 2,000 riders, almost all of whom were faster than I am, I finished 187th. And I started a little late. This is because after racing between rest stops the groups would get more and more tired and wait longer and longer to leave for the next leg.
So, don't believe the false message of FTP and ride within your limits. I would actually feel better finishing in the middle of the pack rather than way near the front which makes me feel that I should have ridden the century rather than the metric (after which I would be tired for 2 weeks.)
I have a pretty good idea of the amount of power I can deliver over the length of a Metric or even a Century and it amazes me to watch groups flying by me (well I am older than dirt now) and then catching them at each rest stop. They overestimate their capacity and run themselves down and then act insulted when I beat them back to the finish while they are falling off of their bikes from exhaustion. Believe me, it isn't because I'm a better rider any more. I just recognize my own limitations.
One of the tricks I've used is to ride the same distance you intend to do a week ahead of your organized ride. This will make you a lot more wary of riding too fast for the distance. Usually though, these people will be in packs and racing each other as if an organized ride was a race.
The last organized ride I did was at the end of 2019 and I caught up with a man on an MTB after the last rest stop. Seeing some broken down old fart next to him he was convinced he could ride with me. So on a course, the end of which was continuous rollers, he gradually slowed down on the top of each rise and would give it everything on the following descent to catch up until he finally blew sky high. That was a bit unfortunate since it was only about 2 miles more to the finish line. Out of 2,000 riders, almost all of whom were faster than I am, I finished 187th. And I started a little late. This is because after racing between rest stops the groups would get more and more tired and wait longer and longer to leave for the next leg.
So, don't believe the false message of FTP and ride within your limits. I would actually feel better finishing in the middle of the pack rather than way near the front which makes me feel that I should have ridden the century rather than the metric (after which I would be tired for 2 weeks.)