Dear Bruce,
Yes, at our age, we do definitely have to warm up. Or so I keep telling my instructor when he wants me to "just to do it" when all we had been doing was low kicks. I warm up hamstrings by doing low kicks slow repetitiously, or running. Then I do static stretches slow and easy-- hold for few seconds, about three times each leg before class. Then, I go into dynamic stretch kicks to the front and side. Then hooks. Then spin heels. Then jump spin heel. That's my progression. And stretch out after class. High energy needed for this. Crescent is easier, energy wise, I think.
PS.I have hamstring problems all the time. too much repetition on other kicks then they tighten to much for this little maneuver. and I'm REAL flexible. :uhyeah: