While I'm not a Zen sort of guy, this is a pretty good book. He talks a good deal about awareness and mindfulness. If you've read Brian's book then you'll get some overall "howto" from this one. The author discusses relaxing, centering, and connecting well with the ground to get more effortless power. While his background is in martial arts the concepts are common to many if not most sports and body activities.
Recommended.
Zen Body-Being: An Enlightened Approach to Physical Skill, Grace, and Power
Peter Ralston, Laura Ralston (Frog Books, 2006)