Continuum’s Height Problem

I like the TV show Continuum and its twisty time-travel switcheroos. I'm always a sucker for those, in any show. I wonder how the various mysteries will be resolved, assuming they are all resolved when the show finishes its run. But the one mystery that I find annoying rather than intriguing is Alec Sadler's height.

In the present, he's about 20 years old. He's shorter than almost everyone else, including Kiera. In scenes set in the future, he's in his mid-eighties. Unless future medicine has solved the problem of people getting shorter in old age, he would have lost some height since his max height. But he still towers over almost everyone, including Kiera. Maybe growth spurts happen after 20, but they must be rare.

There are other time travelers, besides Kiera, and none of them seems unusually tall or short compared to people of today or the future. So unless travel itself does something weird to people's heights, Alec's height is a msytery.