A pilot randomized trial of exercise as adjunct therapy in a heroin-assisted treatment setting

Although the potential of exercise as an adjunct treatment for substance dependence is persuasive in theory, few controlled trials have assessed its effectiveness. Existing research has also largely focused on individuals aiming towards, or having already achieved, abstinence. This study employed a randomized design in a pilot trial to assess the feasibility, acceptance, and effects of an exercise intervention for individuals receiving outpatient heroin-assisted treatment.

50 individuals receiving heroin-assisted treatment at a clinic in Switzerland were invited to take part in the trial. Participants were randomized to 12weeks of exercise twice per week, or a corresponding duration of non-exercise group activities in a comparison condition. Data on attendance, compliance, and numerous psychological and physiological parameters were gathered.

24 individuals were willing to take part in the study. 92.3% of the exercise condition (n=13) were compliant or semi-compliant with the protocol; by contrast, only 54.6% of participants in the comparison condition (n=11) were compliant or semi-compliant (χ₂=7.049; p=0.029). Participants in the exercise condition significantly increased the number of minutes spent exercising at a high intensity level (F(2,44)=3.794; p=0.046; η²=0.159). No other significant interaction effects were observed.

An exercise intervention is a feasible and accepted supplementary therapy to heroin-assisted treatment. Participation rates were high, particularly given the outpatient setting. No evidence regarding the potential mechanisms of exercise as a therapy modality could be identified. Patients in heroin-assisted treatment may require a longer-term exercise programme, specifically targeting particular health parameters, before measurable improvements can be observed.