It's not just age, but fitness will also actually <increase> your required warmup time. The more muscle mass you have, the longer it will take to warm up. I've known track sprinters who tell me that it takes them about an hour sometimes to warm up.
I'm not a track sprinter, but I always liked to warm up with the sprinters. They roll along at about 25 kmh, just fast enough to not slide off the banking at a track like Alpenrose in Portland. And the speed would increase very, very gradually, until we were in a flat out sprint for about the last ten laps 20 to 40 minutes later. But by then, we'd be ready for it.
You get in a warmup with the beginners, and they'd be trying to boost the speed to over 40 kmh in the first five minutes. The more experienced the riders, the longer and slower the warmup. And once the racing starts, these guys who had warmed up slowly and gradually would be averaging over 50 kmh in the mass starts. The beginners who had warmed up at their top speed would be first off the back!
L.