Stop&Go is an intervention program aimed at promoting a healthy and physically active lifestyle for patients requiring inpatient detoxification treatment. The program includes two different phases. Phase I is aimed at understanding the variables related with adherence to healthy lifestyle interventions. Phase II will use the knowledge obtained in Phase I to develop and evaluate an intervention based on Self-determination theory to promote healthy and physically active lifestyles for patients admitted to an inpatient detoxification centre. The Stop&Go intervention is hypothesized to help patients move towards a healthy lifestyle and thus, may bring about changes in patients' (1) knowledge acquired, (2) indicators of healthy habits (e.g., exercise motivation) and (3) psychological well-being and ill-being.

In patients with substance use disorders, exercise could help in the treatment of substance addictions. Interventions focused on promoting physical activity and healthy lifestyle for patients in residential treatment centres and ambulatory settings have been developed in the last years. However, there is a lack of programs promoting a healthy and physically active lifestyle for patients requiring inpatient detoxification treatment. Thus, the plan is to develop an intervention program with such characteristics, namely "Stop&Go".

Stop&Go includes two different phases. Phase I is aimed at understanding the variables related with adherence to healthy lifestyle interventions. Patients with substance use disorders will be invited to participate in focus groups (Study 1) and to respond to questionnaires (Study 2) assessing variables related to exercise and healthy habits (e.g., intention to be physically active). Phase II will use the knowledge obtained in Phase I to develop and evaluate an intervention to promote healthy and physically active lifestyle for patients admitted to an inpatient detoxification centre. The intervention will be based on Self-determination theory postulates and will have two axes: to educate and to motivate. Patients will participate in four practically-oriented training sessions, focused on (1) nutrition and oral hygiene, (2) sleep habits and self-care, (3) physical activity and exercise, and (4) smoking cessation. In addition, the entire inpatient detoxification centre will be adapted to encourage autonomous physical activity and to reinforce the ideas presented in the training sessions.

The main strength of Stop&Go is expected to be the combination of perspectives included in its development (i.e., intervention led by an interdisciplinary team and based on patients' needs). The Stop&Go intervention is hypothesized to help patients move towards a healthy lifestyle and thus, may bring about changes in patients' (1) knowledge acquired, (2) variables related to healthy habits (e.g., exercise motivation) and (3) psychological well-being and ill-being.

Inclusion Criteria:

• Meeting DSM-V criteria for substance use disorder.
• Request for treatment primarily based on substance detoxification.
• Voluntary admission to an impatient detoxification centre
• Age ≥ 18 years old.

Exclusion Criteria:

• Mental disorders that could hinder patient assessment
• Difficulty to answer the survey due to limited literacy or poor Spanish language proficiency.