Preliminary research suggests that physical activity may strongly improve self-controlled decision making. The study, published in the journal Behavior Modification, examined the effect of exercise on delay discounting, meaning the tendency to choose an immediate reward over a larger reward in the future.

“My interest in this topic primarily came from an interest in using pro-health interventions to change behavior. Much of my research is on delay discounting, which is essentially the finding that individuals prefer smaller sooner rewards over larger later rewards (e.g. Would you rather have $10 today or $15 tomorrow?),” explained the study’s corresponding author, Michael J. Sofis of the University of Kansas at Lawrence.

“Discounting tends to be discussed on a continuum of impulsive (high discounting) to self-controlled (low discounting). Excessive rates of discounting (i.e., more impulsive) have been strongly linked to clinical problems such as obesity, problem-gambling, multiple forms of substance abuse, mental issues, and others. Some fairly recent evidence from laboratory studies also suggests that one’s rate of delay discounting can be modified, thus potentially improving multiple behavioral and clinical outcomes.”

“Unfortunately, there were no studies to our knowledge that demonstrated changes in participants’ delay discounting after the treatment team left,” continued. “Specifically, we wanted to know if we could notably decrease discounting rates in our participants in such a fashion that their improved decision making maintained even after we stopped working with them.”

Sofis and his colleagues found that a 7-week effort-paced jogging program resulted in reduced levels of delay discounting. In other words, as the exercise program progressed, the participants were more likely to say they would rather delay gratification to obtain a bigger reward. A follow-up found that the effect lasted for at least a month after the jogging routine had ended.

“I hope that the average person understands three broad points,” Sofis told PsyPost. “First, pay attention to how effortful it feels to exercise throughout each workout. In our study, we first instructed participants to walk/run at what felt like an 8 on a scale of 6-20 (6 no effort-20 maximal effort) and asked participants for their perceived effort after each lap. This allowed us to individualize performance for each participant and may be why we saw improvements regardless of baseline weights and BMIs, experience with sports, age, and mental health status.

“Second, relatively small amounts of physical activity may strongly improve self-controlled decision making (i.e., participants averaged roughly 80 minutes of workouts sessions per week in the current study). Lastly, we found that simply showing up to the workouts was strongly correlated with improvements in self-controlled decision-making (i.e., delay discounting).”

“More broadly speaking, I think this study adds to a small but growing literature that suggests that somewhat common-sense activities may have strong effects on reducing impulsivity and improving our self-control,” Sofis said. “There have been consistent contributions from the Department of Psychology at Utah State indicating that Acceptance and Commitment Therapy and exposure to nature may also be effective ways to improve self-control.”

The findings are promising, but the subject requires more research. The study included relatively few participants and lacked a control group. The researchers also used hypothetical questions as opposed to real rewards to measure delay discounting.

“The biggest caveat of the study is that our participants were predominately women; therefore, how our intervention may affect men is unknown at this time,” Sofis added. “Because participants were regulating their effort levels through our effort-paced intervention, the relative contributions of physical activity and our effort-paced procedure on self-control are unknown.”

“Our team is about to pilot test a smartphone application that remotely provides the effort-paced intervention by harnessing self-reported effort levels and physical activity performance to instruct participants’ effort levels across multiple intervals of an exercise session.”

The study, “Maintained Physical Activity Induced Changes in Delay Discounting“, was also co-authored by Ale Carrillo and David P. Jarmolowicz.