Anyone know of a nerdy source for stretching exercises? I'd love to know exactly how often, and how far to stretch to maximise progress rather than just guess but I've not really found anything that seems to have rigorous justification for their numbers.
https://www.reddit.com/r/Fitness/comments/jjprs/starting_str...
The Reddit user phrakture is awesome and absolutely knows what he's talking about. He contributed quality content very often to the /r/fitness subreddit. Check out those programs he crafted to get more flexible!
Starting Stretching: http://phraktured.net/starting-stretching.html
Molding Mobility: http://phraktured.net/molding-mobility.html
It's not specifically what you asked for, but as I've been learning about mobility work, I've found that the illustrations they use in their free book are especially helpful for learning to identify specific muscles and can help you narrow in on your problem areas in conjunction with other programs.
http://www.amazon.co.uk/Stretching-Scientifically-Guide-Flex...