PHAST: Physical Activity in Substitution Therapy

Overview

The aim is to examine the effect of exercise (EX) training on individuals currently receiving ST - either opiate replacement therapy (ORT) or heroin-assisted treatment (HAT) - for their opiate dependence. Main outcome variables will be: cardiovascular fitness; consumption of substances (e.g. "street heroin", cocaine, cannabis, alcohol, cigarettes) other than prescribed ST or other prescribed medications; substance craving; blood pressure; lung function; resting pulse; social interaction; self-control capacity; objective and subjective sleep; cortisol levels; quality adjusted life years (QALYs); depression; mood. Covariates are current substitution dose and psychiatric diagnoses.

The investigators aim is to carry out a randomized controlled trial comparing exercise training group and a control group of patients receiving substitution therapy (ST). The specific goals of the study are: 1. To understand the exercise preferences, barriers to participation, motivation, experiences and attitudes regarding exercise training in patients under ST. 2. To examine whether a 12-week exercise programme affects the mental health, subjective and objective sleep, quality of life, self-control capacity, substance craving, hair cortisol levels, secondary consumption, cardiovascular fitness, blood pressure, lung function, resting pulse, and social interaction in patients receiving ST. 3. To compare the effects of the EX and control conditions on the above-mentioned outcome variables. 4. To examine to what degree the covariates of heroin substitution dose and psychiatric comorbidities affect outcome variables. 5. To explore to what extent objective variables (cardiovascular fitness, pulse, blood pressure, lung function, cortisol, objective sleep-EEG-parameters) and subjective-psychological dimensions (subjective sleep, social interaction, symptoms of depression and anxiety, self-control, substance craving) are interrelated.