However, it can be stated that three [34] or four [33] weeks of supervised EX may not be sufficient to induce significant additional selleck chemicals changes in anxiety, depression, and abstinence rates and that fitness gains are neither necessary nor sufficient to account for the behavioral and emotional changes reported in most studies.One possible mechanism of action which is often hypothesized regarding the effects of EX is craving reduction. One study [52] investigated the acute effects of EX in detoxified patients, using a crossover design with 10min of either moderate or light aerobic EX on a bicycle ergometer. During moderate EX, significant reductions of craving were observed. However, this effect did not continue after the end of the intervention, and there was a trend towards higher baseline levels of craving in the moderate EX condition.

Therefore, the craving-reducing activity of EX remains subject to further studies.An additional study gives information about exercise attitudes and behaviors in a sample of day-clinic patients [53]. Generally, 75% of patients were interested in EX programs, and almost half of the patients stated to exercise regularly (preferably walking, weight lifting, and cycling). EX was appreciated for providing tension relief, stress reduction, and a more positive attitude. Barriers named by the patients included high costs, lack of motivation, time, knowledge, confidence and physical disability.Hence, adequately powered RCTs are necessary to confirm or disprove beneficial effects of EX interventions in alcohol use disorders, and to disentangle potential mechanisms of action.

3.3. Illicit Substance Abuse/DependenceBesides substitution therapy, established therapies for illicit drug abuse/ dependence include Drug_discovery medication for relapse prevention (e.g., naltrexone) as well as different psychotherapeutic approaches (motivational interviewing, CBT, psychodynamic and systemic approaches, psychoeducation, and social therapy).So far, no studies satisfying RCT-criteria have been published for this specific population. However, eight studies were identified which investigated therapeutic effects of EX in drug-dependent patients (see Table 3). Table 3Studies investigating EX in the therapy of illicit drug abuse/dependence.In these studies, treatment duration ranges from to two weeks [44] to six months [42], with training frequencies ranging from several times a day [41] to twice a week [40].Six studies reported substance-related outcomes like craving, percentage of abstinent subjects, continuous days of abstinence [37, 38, 41�C44], which improved with treatment in all six studies.