stretching

I have read a few things about joint prep and stretching. One of the things i have seen people dois stretch for 5 to 10 minutes before each workout. They never seemt o have anything bad happen to them, why do some people advise 30 minutes, once a week for beginners and 2 a week for everyone esle?

One reason is that most people don't like stretching and you can still make very good progress with once or twice a week stretching. Another is that if you over do stretching you can end up with bad tears that take a while to heal.

With that said I don't think there's anything wrong with some light stretching as part of your warmup, just don't over do it.

It also depends on what your going to work, for example when I work on v sits I need to prep beforehand with passive and active flexibility because it's at the limits of my usable range of motion.