Quick summary: "Hidden rationalists" are what I call authors who espouse rationalist principles, and probably think of themselves as rational people, but don't always write on "traditional" Less Wrong-ish topics and probably haven't heard of Less Wrong.

I've noticed that a lot of my rationalist friends seem to read the same ten blogs, and while it's great to have a core set of favorite authors, it's also nice to stretch out a bit and see how everyday rationalists are doing cool stuff in their own fields of expertise. I've found many people who push my rationalist buttons in fields of interest to me (journalism, fitness, etc.), and I'm sure other LWers have their own people in their own fields.

So I'm setting up this post as a place to link to/summarize the work of your favorite hidden rationalists. Be liberal with your suggestions!

Another way to phrase this: Who are the people/sources who give you the same feelings you get when you read your favorite LW posts, but who many of us probably haven't heard of?

Here's my list, to kick things off:

• Peter Sandman, professional risk communication consultant. Often writes alongside Jody Lanard. Specialties: Effective communication, dealing with irrational people in a kind and efficient way, carefully weighing risks and benefits. My favorite recent post of his deals with empathy for Ebola victims and is a major, Slate Star Codex-esque tour de force. His "guestbook comments" page is better than his collection of web articles, but both are quite good.
• Doug McGuff, MD, fitness guru and author of the exercise book with the highest citation-to-page ratio of any I've seen. His big thing is "superslow training", where you perform short and extremely intense workouts (video here). I've been moving in this direction for about 18 months now, and I've been able to cut my workout time approximately in half without losing strength. May not work for everyone, but reminds me of Leverage Research's sleep experiments; if it happens to work for you, you gain a heck of a lot of time. I also love the way he emphasizes the utility of strength training for all ages/genders -- very different from what you'd see on a lot of weightlifting sites.
• Philosophers' Mail. A website maintained by applied philosophers at the School of Life, which reminds me of a hippy-dippy European version of CFAR (in a good way). Not much science, but a lot of clever musings on the ways that philosophy can help us live, and some excellent summaries of philosophers who are hard to read in the original. (Their piece on Vermeer is a personal favorite, as is this essay on Simon Cowell.) This recently stopped posting new material, but the School of Life now collects similar work through The Book of Life.