**Abstract**

This book chapter presents a review of the main benefits that the practice of physical activity brings to people with severe mental disorder (SMD), as well as highlighting the most significant barriers that hinder their adherence. In this regard, it should be noted that this is a population sector in which sedentary lifestyle habits predominate, showing that physical activity is not only beneficial for physical health but also for mental and social health. However, people with severe mental disorder face barriers in which personal, social, and intervention program factors play a role, what makes regular practice difficult for them and, therefore, to access the numerous benefits it brings.

**Keywords:** Severe mental disorder, physical activity, benefits, barriers, inclusion

### **1. Introduction**

Severe mental disorder (SMD) refers to different psychopathological conditions, such as severe depression, bipolar disorder, schizophrenia, or severe personality disorders, which have a duration of at least 2 years and affect several aspects of the person's life (social, clinical, educational, judicial, etc.) [1, 2]. Due to their high impact on quality of life and their current prevalence, they are considered as one of the major health issues [3]. These are people who, for instance, see their life expectancy reduced by 10–20 years [1].

These individuals are at increased risk of medical problems, mainly associated with sedentary lifestyles, poor dietary habits, and the adverse physical and mental effects of toxic intake or medication effects. Possible secondary medical complications include cardiovascular complications, metabolic syndrome, and the development of diabetes [4, 5].

Among the recommendations to palliate these difficulties, the practice of physical activity stands out, as it has benefits not only on physical but also on personal

well-being and mental health [6, 7]. Through this practice, cardiometabolic complications are affected [8, 9], as well as psychological factors such as mood, self-esteem, and psychological and social well-being, which is also closely related to another common problem in this field, such as stigma toward mental health problems [10].

However, despite the fact that this is a problem with a high incidence among the current population, there are not many studies that focus specifically on the effect of physical activity on people with SMD. This is a topic that has not been formally studied and is mostly based on interventions without follow-up or carried out for short periods of time (1 to 3 months), making it difficult to identify long-term benefits and barriers. Therefore, despite its relevance, there is still a predominant lack of justification for its transfer to clinical routines.

In that sense, this chapter presents a review of the existing literature, with the aim of determining the factors that have a positive effect on the practice of physical activity, as well as the barriers that people with SMD have to face so as to do it. For this purpose, specific attention will be paid to those physical activity programs that have been actively implemented in this population sector, being able to extract the relevant data from them thanks to their empirical analyses, based on the collection of qualitative and quantitative data.
