I first heard of this guy on Joe Rogan's podcast, but the author of this book is a bona fide badass. From Amazon:

"David Goggins is a retired Navy SEAL and the only member of the U.S. Armed Forces ever to complete SEAL training, U.S. Army Ranger School, and Air Force Tactical Air Controller training. Goggins has competed in more than sixty ultra-marathons, triathlons, and ultra-triathlons, setting new course records and regularly placing in the top five. A former Guinness World Record holder for completing 4,030 pull-ups in seventeen hours, he's a much-sought-after public speaker who's shared his story with the staffs of Fortune 500 companies, professional sports teams, and hundreds of thousands of students across the country."

I thought it worth submitting to the MRP community because the mental concepts he uses in training are essential for anyone serious about working out and/or improving themselves. He also has some amazing experience in using his mind to get him through some shitty situations and major life setbacks. He was nearly 300lbs when he first attempted to join the military. There is great motivation in here for hardened MRP veterans and noob faggots alike! He's an alpha male among alpha males.

Can't Hurt Me: Master Your Mind and Defy the Odds https://www.amazon.com/dp/1544512279/ref=cm_sw_r_cp_apa_i_WC3xCbEGXSKW0