I took Thing 3 out for a sprint workout today (he started riding in April and has taken it pretty seriously -- he's to the point of needing some specificity for MTB and road racing). Anyway, it's interesting with us -- he's 5'10" at 134 lbs right now, with a max power around 850W. I'm 6'3" 195lbs and maybe 1400W max (need to do some testing "for reals" sometime before a crit actually starts). We did the sprints on a super hilly loop pre-dawn this morning, just picking landmarks "go for three light poles, starting at that mailbox!"
Funny thing is that for three of the sprints, I had no hope of beating him and for the other three he had no hope of beating me. If the hill is steep enough to keep our top speed below 20mph, he kills/murders me. Anything faster than that, and it's like I'm sprinting against a triathlete, and he has no hope. It's been fun. I'm looking forward to seeing how he develops a power profile and race style. It does suck to be sitting here with a reasonable 330W FTP, and he's solidly beating me on W/kg. It totally shows on the hills now. As recently as last month, I could still take him out on 5 minute climbs, but now, if we're climbing in the small ring, he just rides away and there's nothing I can do about it. I need to drop another 10 lbs, but I am definitely a damned crit racer.