From his website - www.powerspeedendurance.com
Brian Mackenzie is a human performance and movement specialist. He is the innovator of the endurance, strength and conditioning paradigm. He has studied performance and movement since 2001 with altitude, hypoxia, breathing mechanics & methods, along with heat and cold exposure. He has spent a lot of his time training and understanding in and around the water, and desert. He has participated in Ironman (Canada 2004), and has run the Western States 100 and the Angeles Crest 100 mile endurance runs. He co-authored the books Power Speed Endurance, and The New York Times Best Seller UnBreakable Runner.