In the 2000 Sydney olympics the German team pursuit team broke the world record in winning the final in 3 minutes59 seconds. The riders train to maintain approx 670 watts at the front and 450watts following for the 4 minutes. Very intense stuff. If it was a triathlon I think it would look something like a 75m swim with exit from the deep end into a 1k uphill bike into a 400m run across sand.
This is the Australian team winning in 2004 to show the effort http://www.youtube.com/watch?v=Vrwz4laGS4I
Would seem pretty obvious these guys train flat out all the time with huge amounts done at very high intensities to prepare. Luckily there was a study done to see what intensity levels they were training at and some of the results might be a surprise.
Over a period of 200 days leading into the olympics they did 140 days of low intensity/high milage work at 50-60 percent of VO2 max. (see heavy reading below).Very roughly for someone with a max Heart Rate of 190 thats training between 127 and 139 HR.
They spent 40 days riding stage races. Interestingly data from stage races shows that about 80% of the time riders are at less than 80% of VO2max and 20% above that.
They did less than 20 days of near competition pace specific track training. In the 110 days before the final they did 6 days of high intensity tack intervals.
Not for a second am I saying these athletes dont train hard. They do! But they train hard on a huge base of aerobic training. And remember they are training for a short, very intense effort. However the system of small doses of hard work on a big aerobic base is used across multiple sports ranging across short and long efforts including XC running, skiing and rowing.
For an example of someone transforming their triathlon career through aerobic training look no further than Mark Allen. http://philmaffetone.com/markallen.cfm
So when you are out on you bike this weekend keep it relaxed. Dont be afraid to pull off the front if you feel you cannot hold the pace at a reasonable HR. It is perfectly ok for a small group to have the same 2 people at the front all the time if that reflects their current fitness level. I always let my groups have a couple of sprints for the top of a hill or a town sign but only in a controlled way. You should not start a wind-up from the bottom of the hill to get in position! If riders are blown out the back before a sprint starts you went too fast. Simply put for most of your training you should never have to struggle to talk to the person beside you. If you can sing a song you are probably in a good place.