As part of my efforts to illustrate a complementary relationship between physical fitness and moral virtues, I previously detailed how practicing yoga benefits prison inmates. Specifically, research has shown that yoga improves positive mood and decreases stress, anxiety, depression and recidivism in prison populations. And yoga is not the only physical practice that can benefit prisoners. Below, I summarize the advantages of physical fitness in prison by drawing on evidence for yoga, running and weightlifting. These diverse physical practices offer positive behavioral and mental health outcomes among inmates. In turn, this evidence provides further support for the importance of physical fitness in a well-rounded theory of ethics.
Challenges for Prison Populations
Prisons consist of people who have (mostly, barring wrongful convictions) violated ethical norms. Were it possible to improve the ethical behavior of prisoners, a similar approach should work in the general population. In an ideal world, imprisonment for a crime would serve to protect public safety, rehabilitate the offender, or both. Convicts would serve their sentence and return to society no longer posing a threat to the well-being of others.
Unfortunately, that is rarely the case in the real world, especially in the United States. According to the National Institute of Justice, almost 44% of U.S. criminals released from prison are re-incarcerated within a year. In 2005, about 68% of released prisoners were arrested for a new crime within three years. 77% were arrested within five years.
Far from providing a rehabilitative environment, prison life induces stress, anxiety, hopelessness and depression. Prisoners face isolation, boredom and violence, and many of them come to prison burdened by low self-esteem or drug addiction. Take a person who has violated ethical norms and has a self-destructive streak and place him in an environment that exacerbates negative emotions, and it’s no wonder convicts are not often upstanding citizens upon their release.

Yoga in Prisons
However, the practice of physical fitness in prison populations has demonstrated remarkable success in improving inmates’ mental and emotional health and reducing recidivism. As I described in my previous article on fitness in prison, prisoners who practice yoga experience increased positive mood and attention and decreased anxiety, stress and depression. At the Richmond City Jail in Virginia, a mental health program that included yoga reduced recidivism by 18%. A 2008 study of North Carolina inmates found taking four or more yoga classes cut recidivism from 25.2% to 8.5%.
Running in Prisons
But yoga is not the only physical practice with such benefits. A large body of research has established a link between aerobic exercises like running and cognitive clarity. Vigorous aerobic exercise triggers the production of new neurons in the brain—the only activity known to do so. Thirty to forty minutes of vigorous exercise increases blood flow to the brain’s frontal lobe. This area is associated with clear thinking, planning ahead, focus and concentration, goal-setting and time management. Many prison inmates struggle with these capacities.
In a 2016 documentary titled Laps, inmates at California’s San Quentin State Prison explain their battles with stress and thinking clearly. One inmate, who introduces himself only as Eddie, calls running “my drug” and says it offers a sense of escapism. Another, Mike, says he runs to relieve stress and remove clutter from his mind. Mike says running helps him to sort out his thoughts, allowing him to better handle confrontations and avoid troublesome situations.
In short, running can help ameliorate many of the issues that plague prisoners, like drug addiction, stress and conflict. Given the scientific evidence and first-hand accounts, runnning should be a valuable approach to physical and mental fitness in prison.
Weightlifting Fears
On the opposite end of the exercise spectrum from running, weight training offers similar benefits. In a 1987 study, researchers randomly assigned 40 (non-incarcerated) women with depression to either an eight-week running program, weight training program or no program (control group). Compared to the control, both running and weightlifting significantly reduced depression.
However, the U.S. government has curtailed weightlifting in prisons in apparent fear of producing stronger prisoners who could overwhelm guards or cause greater destruction in society upon release. In his dissent to a 2011 ruling that crowding in California prisons constituted cruel and unusual punishment, Supreme Court Justice Antonin Scalia described the prisoners in question as “fine physical specimens who have developed intimidating muscles pumping iron in the prison gym.” A 1996 amendment prohibited the federal Bureau of Prisons from purchasing “training equipment for boxing, wrestling, judo, karate, or other martial art, or any bodybuilding or weightlifting equipment of any sort.”

Weightlifting in Prisons
But the research doesn’t support those fears. In a 1999 study, 202 incarcerated males in the Texas Department of Criminal Justice completed psychometric evaluations before and after either a period of weight training or a control period of no training. Compared to the untrained group, measures of verbal aggression, hostility, and anger significantly decreased in the weight training group.
Sociologists and prison officials have pushed back on limitations on weightlifting equipment. In addition to research showing that weight training actually decreases aggression, some prison wardens have noted that idleness is the greatest threat to prison order. Lifting weights provides prisoners a focused activity and makes them less of a threat.
Ex-New York State inmate Daniel Genis describes his experience with strength training in prison: “The discipline and dedication required by weightlifting, plus the confidence it inspires, make for a better man… Many prisoners are former drug addicts; many suffer from low self-esteem, the result of being poor, ignorant, and generally unsuccessful in life. The weight yards help them to see a better version of themselves, and offer them a concrete achievement in a place meant to degrade and diminish.”
Maurizio Guarrata, who taught CrossFit classes in an Italian prison, concurs. Prisoners “found themselves in a more positive mood and [are] able to deal with menial obstacles in life more aptly,” Guarrata wrote in an editorial for Breaking Muscle. “They’re achieving things and sticking with it.”
Guarrata adds that his inmate students “discovered a community that helps them form new, healthy habits and avoid relapse.” One prisoner told him, “At one time, we all gave our focus to addiction, but it’s not that hard to take your focus and turn it towards a positive addiction.”
The Ethics of Fitness
Thus, a large body of evidence indicates various aerobic and anaerobic exercises can have positive effects on prison inmates. Yoga, running and weightlifting can help reduce stress, anxiety, depression, aggression and anger. We have direct evidence that yoga reduces recidivism among inmates after their release. Given the similar benefits of running and weightlifting, there is good reason to believe these forms of exercise can also help rehabilitate convicted criminals.
This research provides additional support for the non-physical benefits of physical activity. If a dedicated physical practice can improve the attitudes and ethical behavior of those convicted of violating ethical norms, it stands to reason that we can all benefit from such a practice. Physical fitness belongs in a well-rounded theory of ethics because it contributes to non-physical ethical domains.