+1 on the Do Not Look at the Computer. Make your effort level the thing that matters.

A group of us went out for a fairly long ride one day (we do a 'perimeter of the town' thing on Memorial Day or Fourth of July), and three youngsters (under 30 ) had emailed to make sure we weren't going to go too fast for them...

We sailed for a while, then turned, then turnedb ack into the wind. We all started working That Much Harder, for about two miles, at which point I said "here's where we decide how much fun we're going to be having in ten miles. Let's back it off a tad." I backed off to a sustainable effort level.

Turns out one of the people on the ride was planning to do a multi-day tour, and had been worried that she wouldn't be able to ride long distances if it were windy... because before wind had wasted her... because the groups she was with had always revved up the effort.

So it's a choice. You can rev up the effort and it will make you mighty, or you can ride at the same effort level you usually do and it will just take a little longer and still make you mighty, but probably less cranky :-)