A lawyer and former addict, Shanahan found that exercise and nutrition were cornerstones of his recovery, so, he says, "I took the time I used to waste at bars and partying and put it towards learning as much as I could about exercise and nutrition science." Meticulously researched, the book is intended to fill a niche, as the author himself could not find any titles on the subject of nutrition and exercise for people in recovery during his own journey.

"The available books were out-of-date," Shanahan says, "and many self-published books contained facts or conclusions that were not supported by science, but rather were based on the author's subjective opinion. Therefore, I wanted to create an evidence-based ‘one-stop shop' where people would be able to get basic information on these topics. I wanted people in recovery to know my conclusions are backed by science, not simply my opinion."

So how important are things such as staying active and eating right in recovery? More than many might assume. Shanahan says recovering addicts should keep these issues front and center. Those who integrate exercise and smart dietary choices into their recovery have, Shanahan says, "lower relapse rates and happier lives as sober people." Diet and exercise are also cornerstones of the 12-step program, as Shanahan is quick to point out. "Bill W. and Dr. Bob, the two founders of the 12-step program, as well as Dr. Silkworth, the doctor they relied on heavily and who was a pioneer in treating alcoholics, all agreed that nutrition and other lifestyle modifications were of great import to helping people stay sober. Bill W. actually categorized comfort foods as the ‘sister foods to alcohol.'"

Shanahan's book also addresses how those in recovery have different considerations and hurdles than other people. It's this focus that makes Spiritual Adrenaline a practical guide for a recovering addict looking to get active. Not only do addicts need to avoid isolating behavior—Shanahan notes than several sober living groups now incorporate "active lifestyle" practices—they also need to be mindful of their existing health concerns when starting any new exercise routine.

On this front, Shanahan says, recovering addicts should work with personal trainers, nutritionists, "and other people who can evaluate their health history and blood work and can help them develop a safe active sober lifestyle plan." In the book, he clearly explains all the initial steps to take; he notes that he has "not seen any other book or plan that takes these issues into consideration."

Food-wise, Shanahan also has specific modifications for recovering addicts designed around sugar, caffeine, and comfort foods. Because caffeine and high-sugar/high-fat foods are particularly alluring to those in recovery—as Shanahan says, "these foods break down similarly to alcohol and prompt the production of dopamine and/or endorphins"—a solid nutrition plan can be key to remaining sober and healthy.

Ultimately, Shanahan said, the book helps recovering addicts with a self-care routine tailored specifically for them. "Exercise is self-care," he said. "I abused my body with substances and the lifestyle that comes along with substances for years. Self-care is the complete opposite of active addiction, and so exercise is among the most powerful recovery tools available. The same is true for nutrition."