This whole website is gold. There are free ebooks with dog training anecdotes, as well as a really great dog training guide called training levels of which there is a free (out-dated but still good) and for-sale version.
Really nice post about warming your dog up before asking them to do hard work, which makes perfect sense. No human athlete would be expected to perform without first preparing their body.
This video is amazing and I wish I was skilled enough to get Betsy to do this.