The funny thing about the M30-35 division (in cycling, running, and triathlon), is that it seems bimodal. The very pointy end is uber-fast - pro/elites dominate the #1/2 spots in most big races. However, there's a huge gap between the pros and the fast 'AGers', and in running / triathlon, it's often easier to get into the FOP of M35 than it is in M<30 or M>40. I'm speculating that a lot of this has to do with child-rearing - it's hard to train very hard, 15+ hrs per week, when you're dealing with young kids between 0 & 7 yrs old and holding down a full time job. The pros/elites often do the sport as a career, so they don't have to juggle, but for the rest of the new dads (& moms), kids generally will give the FOP competitors a huge hit on their training.

Then you turn 40+, kids learn to watch TV and do their own activities, and you get into the most competitive AG by far in triathlon - 40-50. Not sure if it's just as competitive in cycling, but it is in tri. For running, not so much - there seems to be much more of an age-related speed decrease in running despite age. Even in the fastest masters running clubs, I'll be surprised if more than a few can outrun me, but in a masters bike race, I can count on 10+ killing me, and I'm probably 'equally' fast on bike/run given training and ability at M35-40.