cyclezen

so I'm hoping this just a 'reaction' to what seems a repeated counterpoint of'eliteism' in the thread about the OP's comments. Certainly the cycling universe is larger than any of us. Whether you ride a Bike Friday, Bent or are a Tri-Geek, messenger or Sunday Poseur matters very little on a 'value' scale - its really all good.
Now, the OP's tone might seem a bit high & mighty and the physical stuff might be more 'exaggeration' than reality (I hope so). Most of the points are well taken. I might personally disagree with some, slightly; but overall for a high level training ride with a single mindset, its ok.
More general might be the point that 'jumping in' on any seemingly organized ride/thing is prolly done gingerly with much awareness to what the deal seems to be. If you're welcome, it'll be obvious soon enough. If you're not 'suited', that should hit you in the face quickly enough also; without need for external intervention.
SO, how does one 'break in' to a ride like this?
Surprisingly the old 'apprentice'/journeyman/master concept works quite well. If you really 'need' to be able to ride with this kind of group, find a way to work 'up' in both strength and especially knowledge/skill.
Some riders clearly have much more muscle than experience while 'others' can't muster enough 'juice' out of their legs anymore, despite all the experience they've accumulated. Be accepting of your own capabilities and make it 'fit' or find another venue. If you approach a group in that fashion, they'll usually cut you enough slack to give you the best chance of fitting in.
If that group can ride this strongly, then they certainly might be 'elite' in their own realm.
If you wanna get there, then consider good advise, even if it comes across a little shrill.