Yup, the muscles tend to shorten if you don't stretch them after training/exercise.
Pilates, yoga or some specific stretches would probably do you. Other than the stretchiness aspect, Pilates is aimed at strength/core stability rather more than yoga AFAIA (to be fair I've been doing pilates for years, but only the odd taster of yoga).
In fact just doing a class of Pilates a week plus a bit more over the rest of the week in odd moments managed to keep the cobwebs off over a couple of years when I wasn't cycling much or managing to get in the gym for weights - and in the period prior to that when I *was* cycling/doing weights frequently, if was a good complement. I'd recommend doing some classes at least to begin with to get the breathing/basics right.
There mebbe others I ought to do, but those that I tend to do having just got off a bike are:
hip flexor/quadriceps
http://www.livestron...exor-stretches/
(there's a second version where say the r heel goes to the l. buttock)
Hamstring stretch (there's one that's a bit like a lunge, but you can push the front/back foot further away - like approaching the splits - to give more stretch in the hamstring - can also put the elbows on the floor to the inside of the front leg if you can reach. Careful with it tho', I've managed to overstretch in the past...)
Adductor/inner thigh stretch
Calf stretch (rather than the standard pushing aginst the wall, stand on the edge of a step - cycling shoes help - and just let heel drop below step to stretch calf.)
Pilates rolldown (a kinda one-vertebra-at-a time movement, plus a hamstring stretch)
I don't normally do any glut. stretches other than when I'm specifically doing Pilates, but some here:
http://www.lower-bac...-stretches.html
Might be some other useful stuff in
http://www.livestron...body-exercises/
http://www.livestron.../hip-stretches/
but it's taking a bit too long for me to find..
