Flexibility is such an under-rated component of physical fitness, and in a program as intense as P90X®, it might seem like stretching for an hour is a joke compared to the intensity of the other workouts. Is it far less intense? Yes. Should you just skip it then? Absolutely not!
Stretching properly and effectively has many benefits, including workout recovery, injury prevention, and increased performance. The better you perform, the faster you see results, so that alone should motivate people to take the time to stretch.
The majority of the exercises that are included in the Stretch X DVD are movements that were taught in earlier workouts, including Yoga X. There are some new stretches as well, but it isn't just the new stretches that give Stretch X its value - it is the fact that you are doing the stretches when you aren't completely wiped out from a really intense workout!
During each of the previous P90X workouts, even though Tony Horton always does a great job of warming you up as well as cooling you down, your mind is still pretty scattered at the end of a workout simply because it was so intense. Tony is telling you to hang your arms down and rock back and forth, but you're thinking about just face planting on the floor…
During Stretch X, you are not tired at all, with the exception of the residual soreness that most people will be feeling from the previous workouts. However, that isn't to say that you won't need to push yourself to your limits, just as you do with all of the P90X workouts. In Stretch X, you are simply doing it via effective stretches, rather than challenging resistance or cardiovascular exercises.
Overall, if you approach the Stretch X DVD with a calm and peaceful state of mind, you will get the most out of it. Be grateful for the wonderful break that it is from the high intensity workouts that you've become accustomed to, and just spend an hour taking care of your joints, and relaxing your mind.
The only caveat to all of that is to be sure - as with any workout - that you don't overdo it. It is very possible to stretch too far, or to apply too much force to a stretch. If you end up with that type of an injury, you can count on being out of the P90X game for at least a week, if not more. For that reason, listen to Tony's advice during the workout, stretch effectively and properly, and just enjoy the down time.