Physical exercise linked to improved inhibition and working memory in substance use disorder

Compared with control groups, physical exercise produced meaningful improvements in two key executive functions: inhibition showed an effect size of Hedges's g = 0.47 (95% CI: 0.29 to 0.65, P < .001), and working memory showed g = 0.42 (95% CI: 0.16 to 0.69, P = .002). However, cognitive flexibility—the ability to shift between mental tasks—did not reach statistical significance (g = 0.51, 95% CI: −0.22 to 1.24, P = .170). Subgroup analysis suggested that sessions lasting 46–60 minutes, performed 5 times weekly for 8 weeks, may optimize working memory improvements, though these findings are exploratory and hypothesis-generating. The review notes that while the evidence is encouraging, the relatively small number of studies and modest effect sizes mean results should be interpreted cautiously and that further investigation into cognitive flexibility is needed.

The magnitude of improvement in inhibition (g = 0.47) and working memory (g = 0.42) are modest but clinically meaningful for a complementary intervention in SUD rehabilitation. The failure to improve cognitive flexibility (g = 0.51, not significant) is notable and suggests that exercise may benefit some executive domains more than others—an important distinction for treatment planning. Subgroup findings hint at a dose–response relationship: 46–60 minute sessions at 5×/week for 8 weeks showed the strongest working memory gains, but these are exploratory results that require confirmation in larger, pre-specified trials. The heterogeneity in study designs and intervention types (aerobic vs. resistance vs. combined) likely contributes to variation in effect sizes, and the overall quality of evidence, while moderate, is limited by small sample sizes in individual trials and potential publication bias.