If you're reading this you got an e-mail from me and read the part about doing the "lunge matrix" as a warmup routine. While this term may sound bizarre or even a bit sinister, it's fairly straightforward and you can see a video that explains it all here.
As for stretching, it's a good idea to spend 10 minutes or so doing stretches soon after you've finished a run. What specific stretching exercises to do is a question with a million answers; google "post run stretches" and you'll see what I mean. Here's a good example of a simple routine that's easy to do; you can tailor it to your needs.
Any questions about this feel free to contact me via phone or e-mail.
