Stretching exercises will always changing.
They're mostly yoga poses and they're going to be more and more challenging.
Because flexibility is very inmportant when you're doing for example leg sequences or dance cardio.
Do each pose for about 20 seconds.
Bikram Yoga poses are very great after your cardio!
You don't have to do full 90 minutes session to get benefits from hot yoga,
10-15 minutes after your workout are good enough.