Dose-response Effects Of Resistance Exercise To Ameliorate Craving And Factors In Methamphetamine Use Disorders

PURPOSE: Exercise has been recognized as a potential non-invasive adjunct to promote recovery for methamphetamine use disorders (MUD). The benefits of both aerobic exercise and resistance exercise (RE) have been observed. However, the issue of optimal RE intensity for MUD has not been studied systematically. Thus, we studied the best RE intensity that affects MUD cravings and factors. METHODS: 128 MUDs (34.73 ± 5.65) meeting DSM-V criteria were recruited, adhering to the Declaration of Helsinki. All were randomly assigned to complete 40 min of RE in a low-intensity (30%-35%1-RM) RE group (LIR), a moderate-intensity (55%-60%1-RM) RE group (MIR), a high-intensity (75%-80%1-RM) RE group (HIR) and a control group (CON). Craving was measured by Visual Analog Scales before, during, and immediately after exercise and 40 minutes after exercise. Color-word Stroop task, n-back task, and more-odd-shift task were used immediately after exercise and 40 min after exercise to test inhibition, working memory, and cognitive flexibility of EF, respectively. The amount of change (denoted by ∆) between post- and pre-exercise was used for ANOVA and trend analysis. RESULTS: At immediately post-exercise, ∆craving for MIR was significantly more negative than LIR (p < 0.001, Cohen’s d = 0.98); ∆craving for both MIR and HIR were also lower than CON at 40 min post-exercise (ps < 0.001, Cohen’s d ≥ 1.15). Trend analysis showed a U-shaped quadratic relationship between RE intensity and ∆craving during exercise, immediately after exercise, and 40 minutes after exercise (ps < 0.001), implying that craving was most decreased in MIR. The ∆inhibition and ∆working memory score improved only in MIR compared to the other groups (ps < 0.05, Cohen's d ≥ 0.44). The ∆cognitive flexibility score was remarkably raised in all REs (ps < 0.001, Cohen's d ≥ 0.724). Trend analysis suggested a cubic curve relationship with RE intensity to inhibition function, and a quadratic curve relationship with RE intensity to working memory and cognitive flexibility, all indicating a better effect of MIR. CONCLUSION: RE was effective in reducing MUD craving and improving EF. There was a significant dose-response relationship between RE intensity and craving and executive function, meaning that moderate-intensity RE resulted in more ameliorative benefits for MUD. Project of Social Science Foundation for Youth in China (20CTY018), Philosophy and Social Science Planning Program of Zhejiang Province (22ZJQN31YB)