Why does a middle-aged female psychotherapist take up boxing having previously been repulsed by the sport?
US-based Binnie Klein attempts to answer this in her recently published memoir, Blows to the Head: How Boxing Changed My Mind. It is a provocative tale of an unlikely midlife transformation.
Ms Klein, 59, took up boxing at the age of 55 when she spotted a pair of boxing gloves during a physiotherapy session in the gym.
She tells People: "Something called out to me."
She started training with a coach and was hooked. "For me, it was about the empowerment of feeling my strength and overcoming stereotypes, particularly about Jewish people being pale scholars and not athletes. I was less fearful than I thought."
She says the reaction from friends was the same. "Everyone raised their eyebrows and was mystified, so I decided to write the book."
She spent time researching the history of Jewish boxers, their families and their professional world.
Ms Klein, who lives in Connecticut, is a psychotherapist in a private practice and a lecturer in the Department of Psychiatry at Yale
She also hosts a popular music and interview show on non-commercial radio station WPKN-FM.