Effects of an outdoor exercise program in persons with schizophrenia: Study protocol

doi:10.21203/rs.3.rs-4305748/v1

Background: Schizophrenia is a chronic psychiatric disorder that affects around 1% of the population worldwide. Regular physical activity and exercise has been proposed as a non-pharmacological strategy for prevention and management of the disorder. Outdoor activities such as aerobic training can be an effective approach to promote health. The study will evaluate the feasibility and effectiveness of a 24-week outdoor exercise program and the long-term effects of a 12-week follow-up on the physical and mental health of persons with schizophrenia. A detailed description of the rationale, design and methods of the protocol study will be provided.

Methods: The study will be a quasi-experimental controlled trial using a parallel-group design with multiple assessments over an 8-month period. The study will comprise outpatients between the ages of 18 and 60, clinically diagnosed with schizophrenia. Participants will be allocated to the experimental and control group. The experimental group will perform outdoor exercise twice a week, switching between walking and cycling for 24-weeks, while the control group will continue with regular daily activities. Assessments will be carried out at baseline, post-intervention and at 12-week follow-up. The expected results will be improvements in functional capacity, physical fitness, physical activity levels, self-esteem, motivation to physical activity and quality of life. Also, improvements in anthropometric measures will be expected.

Discussion: The study protocol and future results will add knowledge about the beneficial contribution of outdoor exercise on mental health policies. This study may also contribute to provide guidelines on exercise prescription for persons with schizophrenia.

Schizophrenia

aerobic exercise

urban outdoors

physical health

mental health

The COVID-19 pandemic has generated a boom for outdoor recreation for different activities with increased changes of lifestyle and routines. Primarily outdoor activities performed daily during this period were walking, hiking, running, biking, gardening, picnicking, and beach activities. Due to the lockdown measures imposed to the populations, many indoor activities have moved outdoors when possible. More physically demanding activities such physical activity (PA) and exercise outdoors were very trendy (1). Outdoor activities can be performed in green spaces, such as urban and natural parks, and in blue spaces, such as sea, lake, rivers, which can be referred to as a natural environment. Engaging PA in a natural environment presents non-invasive and cost-effective solutions that have implications for mental health and obesity in both clinical and general populations (2).

Specifically, outdoor PA is linked with increased fitness and improved cardiovascular function, as well as reduced blood pressure, obesity, resting heart rate and a positive influence on other health markers (3). These benefits translate into a reduced risk of several major diseases such as myocardial infarction (4), types of cancer (5), stroke and type 2 diabetes (6). Two systematic reviews have examined how the environmental setting influences the mental health benefits of PA among the general population, comparing PA in natural environments versus indoor settings. One study (7) reported a strong association between PA in natural environments enhancing feelings of revitalization, positive engagement, energy levels, and decreased levels of tension, confusion, anger, and depression compared to indoor physical activity. Lahart, Darcy (8) also reported an improvement in psychological outcomes in terms of affective valence and enjoyment compared to indoor activity. However, inconclusive findings were identified regarding the effects on energy, calmness, tension, anger, and depression (8). Physical activity when performed in an outdoor/green/alpine environment improves mental health (9).

Moreover, outdoor PA is not only presented as supporting the prevention of mental disorders, but also in its recovery (6, 10). For example, Hufner, Ower (9) suggests that therapeutic programs for persons with somatoform, depressive and anxiety disorders should consider taking the benefits of natural outdoor environments. Similarly, Lin (11) argued about the beneficial influence of outdoor exercise for women on anxiety reduction.

It is known that persons with severe mental disorders have a lack of motivation for PA and higher levels of sedentary behaviour (12) that is associated with a higher risk of cardiovascular disease and premature death (13, 14). Schizophrenia is classified as a severe mental disorder that affects around 24 million people worldwide (15) and is considered the most disabling psychiatric disorder (16). Schizophrenia is ranked on the top 20 causes of significant disability worldwide, affecting both developed and developing countries (17).

There is a small but interesting body of research that demonstrates the potential benefits of outdoor exercise in persons with schizophrenia. Outdoor cycling significantly improved fitness measures, even with low intensity, quality of life and self-esteem (18). Similarly, a 16-week outdoor cycling program reduced psychiatric symptoms (psychotic, depressive, and anxiety) and improved cognitive functions and motivation to exercise in persons with schizophrenia (19). However, the evidences about the potential physical and mental health benefits of outdoor exercise in this population are limited. Moreover, it is unknown if the benefits of outdoor exercise can be sustained overtime.

The aim of the study will be to evaluate the feasibility and effectiveness of a 24-week outdoor exercise program and 12-week follow-up on the physical and mental health of persons with schizophrenia. Therefore, a detailed description of the rationale, design and methods of the protocol study will be provided.

The study was designed as a quasi-experimental, 24-week outdoor exercise program and 12-week follow-up in persons with schizophrenia from Porto city, Portugal (Figure 1). This protocol follows the Standard Protocol Items: Recommendations for Interventional Studies (SPIRIT) 2013 checklist (20).

Trial design

This study is a multicenter quasi-experimental controlled trial with a parallel design, that will be conducted in different public and private settings (e.g., general hospitals, psychiatric hospitals, day-care centers and local community centers) for outpatients. Advertisements will be made via phone calls and presential. In order to motivate participants about the exercise sessions, a short presentation session will be provided to exemplify and illustrate a typical session.

Eligible participants will receive a complete explanation of the study purposes, risks and procedures. Following rigorous ethical procedures, informed consent will be obtained from interested participants. After agreeing to participate and according to availability, participants will be allocated into a 24-week experimental group (EG) or into the control group (CG) (see Figure 1). All CG participants will follow with the usual daily routine.

Participants (EG) will be assessed at baseline, after 24-week of intervention, and 12-week follow-up after the end of intervention (Table 1). At baseline, sociodemographic (e.g., age and years of formal education and general clinical data (e.g., presence of comorbidities, pharmacological treatment) will be collected through a structured self-reported questionnaire. Mental health measures, such as self-esteem (Rosenberg Self-esteem), motivation for exercise (Behavioural Exercise Regulations Questionnaire) and quality of life (WHOQOL-Brief) will be assessed using different self-reported questionnaires. Physical health measures such as functional exercise capacity (6-minute walking test), physical fitness (Eurofit) and physical activity levels (GTX3) will be assessed by different field tests.

The standard software ActiLife version 6.9 (Actigraph, Florida) will be use to reduce the raw activity data from the GTX3 triaxial accelerometer into daily PA. A minimum recording of 8-h/day will be the criteria to accept daily PA data as valid. Individual data will only accept for analysis if at least three days of 480 minutes will be successfully assessed. To determine the time spent in PA of different intensities, the following counts intervals (counts/min) will be considered: sedentary physical activity (SEDPA) from 0 to 99 counts/min, for light physical activity (LIGPA) 100 to 2019, 2020 to 5998 for moderate physical activity (MODPA) and ≥5999 for vigorous physical activity (VIGPA) (21).

Data collection will be performed by well-trained and experienced researchers. The same evaluator will be responsible to perform the same procedures along the three assessment periods.

Table 1. Schedule of study protocol

Month		Jan	Fev	Mar	Apr	May	Jun	Jul	Aug	Set	Oct
		Day of the month
Bike Approach		12	2
Baseline Assessments			2 to 14
Intervention			14					27
Post-program assessments								27 to 29
Follow-up								29			21
Follow-up assessments											21 a 28
	Jan= January; Feb= February; Mar= March; Apr= April; Jun= June; Jul= July; Aug= August; Set= September Oct= October

Participants

Eligibility criteria

Inclusion criteria will include outpatients with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders – 5 (DSM-5) (22) in a stable clinical situation with no changes in the antipsychotic medication for one month prior to the program, aged between 18 to 60 and living in the community.

The exclusion criteria for this study will include: inability to speak and understand Portuguese, inability to concentrate for at least 20 minutes (as determined by the treating psychiatrist), substance use disorder or recent substance use within the past six months, hospitalization within the preceding three months, uncontrolled psychiatric symptoms, diagnosis of intellectual disability, and presence of cardiovascular (e.g., uncontrolled hypertension defined as systolic blood pressure >200 mmHg or diastolic blood pressure >110 mmHg, cardiac comorbidities), respiratory (e.g., severe chronic obstructive pulmonary disease, uncontrolled asthma), neuromuscular, and endocrine (e.g., uncontrolled diabetes) disorders that may contraindicate exercise.

Study intervention

Experimental group: exercise training

A 24-week outdoor exercise program will comprise 50 minutes sessions twice a week. The outdoor exercise program will combine walking (or jogging, short runs) and cycling (in different speed) using the facilities nearby the Faculty of Sport, which include green spaces and a park with a small course of water and different kinds of road pavement. Every session will be performed outdoors in small groups. In case of bad weather conditions, the exercise will be conducted indoor using the treadmill and stationary bike located in faculty gym.

In the first 12-weeks, participants will spend 10 minutes setting daily goals and performing warm-up exercises such as knee lifts, squats, lunges with long strides, heel lifts, and stretching. This will be followed by 30 to 35 minutes of walking or biking at a maximum heart rate of 65% to 75%, and finally, 10 minutes for cool-down exercises and discussing the day's achievements. Over the final 12 weeks, the routine will start with 5 minutes dedicated to setting daily goals and warming up, followed by 10 minutes of physical fitness exercises such as squats, lunges, sit-ups, planks, and balancing on one leg. Then, there will be 30 minutes allocated for walking or biking with a maximum heart rate of 75%-85%, and the last 10 minutes will be for cooling down and reflecting about the day's accomplishments.

The research team will closely monitor and regulate the duration and intensity of the exercise program, encouraging participants to enhance their compliance and attendance. Initially, for the first 12 weeks, activities will be prescribed at 65%-75% of maximum heart rate, tracked using portable heart rate monitors worn by participants during each session (Garmin Vívosmart 4). After this period, intensities will rise to 75%-85% of maximum heart rate, remaining consistent until the program's conclusion. To assess participants' perceived exertion, the Borg scale will be employed after each session. Additionally, participants will review and adjust their personal goals with the research team before and after sessions to enhance mood and motivation (19).

Experimental group: 12-week follow-up

During the follow-up period, participants will receive encouragement to engage in exercise through frequent but brief phone interactions with the exercise professional. While weekly exercise supervision will not be provided, participants are encouraged to utilize the same public green spaces for their physical activities. Adherence to the 12-week follow-up will be assessed by querying participants about their continued exercise routines, including the frequency and type of exercise maintained. Adherence will be defined as participating in at least one activity per week.

Control group

Participants will follow their regular routine. However, participants who eventually engage in new activities or interventions must advise the researchers. Participants of this group will be contacted by the researcher to perform all the assessment moments of the study.

Outcomes

Physical outcomes will be evaluated by the six-minute walking test (6MWT) to estimate the functional exercise capacity of the participants. The participants will walk as much as possible for six minutes on a specific flat surface, and their changes will be recorded based on the distance covered in meters (23, 24). The Eurofit test battery will be applied to evaluate the participants’ physical fitness (25) and will include assessments of whole body balance (flamingo balance), speed of limb movement (plate tapping), flexibility (sit-and-reach), explosive strength (standing board jump), static strength (hand grip strength), abdominal muscular endurance (sit-ups) and running speed (shuttle run) (26, 27). Lastly, the GTX3 triaxial accelerometer (Actigraph, Florida) will be utilized to objectively measure habitual PA. Participants will be instructed to wear the accelerometer for 7 consecutive days, positioning it on the right hip using an adjustable belt. Exceptions will be made for time spent sleeping and engaging in showering or other water activities. Participants will be advised to maintain their usual activity routines. Validity criteria will require at least 3 days with 480 minutes of recorded activity.

Regarding anthropometric measures, height will be measure using a Holtain stadiometer (Holtain Ltd., Crymmych, UK) and record in centimetres. Weight will be measure to the nearest 0.1 kg with a Seca weight scale. Body mass index (BMI) will be calculated by the ratio between weight and height (kg/m²). Participant waist and hip circumference will be taken.

The mental health outcomes will be assessed by Rosenberg self-esteem questionnaire validated for Portugal (28). Rosenberg Self-Esteem Scale is a 4-point scale consisting of 10 questions, 5 positive and 5 negative with scores ranging from 10 to 40. Higher scores indicate better self-esteem (28). The reliability was evaluated among outpatients with severe mental disorders, demonstrating an internal consistency exceeding 0.80 (29). The Behavioural Exercise Regulations Questionnaire (BREQ-3) consists of six subscales assessing amotivation, external, introjected, identified, integrated regulation and intrinsic motivation (30, 31) and will be used to assess the participants’ motivation for exercise. The validity and reliability of the Portuguese version of the BREQ-3 (32) was confirmed for individuals with schizophrenia, indicating its suitability as an assessment tool for this population. Also, the Portuguese version of the World Health Organization Quality of Life Scale – Brief Version (WHOQOL – Brief) (33) will be used. The WHOQOL – Brief includes 26 items categorized into four domains: (i) physical; (ii) physiological; (iii) social relationships; (iv) environment and two questions related to global perception of quality of life and health. The Portuguese adaptation of the WHOQOL-BREF demonstrated strong validity and reliability, with a correlation coefficient of 0.65 and a Cronbach's alpha of 0.92 (33).

Confounders

As possible confounders, we will control the demographic variables (e.g., age, gender, education, marital status, employment), the clinical variables like the years of psychiatric disorder, psychotropic medication and smoking (cigarettes/day).

Statistical analysis

Descriptive statistics will be taken for normality, means and standard deviations. Differences between groups at baseline will be assess using the independent-samples student’s t-tests for continuous variables and Ficher’s exact test for categorical variables. The student’s t-test for paired samples and Wilcoxon test will be used to determine changes within the groups from baseline to post-program. Correlation will be analysed using Pearson’s correlation coefficient. A repeated-measures ANOVA with Bonferroni adjustments will be used to compare changes in the outcomes between treatments over time (treatment x time) as appropriate. All analysis will be computed with SPSS (version 27) with the significance level set at 0.05.

Our intention is to share the findings of the study by publishing papers in scientific journals that undergo a rigorous review process, ensuring quality and peers’ recognition. Also, partial findings will be presented at conferences held at both national and international levels. The results will be shared with the institutions from where the participants were recruited during formal meetings that will be scheduled with the multidisciplinary teams of each multi-centre. A formal oral presentation will be provided as well as written information to support the discussion of the main findings of the study. The participants will also be invited for a formal meeting to share and discuss the main findings of the study. Also, each participant will receive an individual report form highlighting the main achievements/progress and identifying skills that can be improved. General recommendations and guidelines to maintain regular outdoor exercise will also be provided. Specifically, control group participants will be invited to participate in outdoor exercise activities that will be purposively implemented after the end of the research to promote adherence and motivation to exercise.

This study describes the protocol implemented to determine the feasibility and effectiveness of a 24-weeks outdoor exercise program in physical and mental health of persons with schizophrenia who are part of the "Mental Health on the Move" project. This project began in 2010 and is an on-going intervention aiming to promote active lifestyles in the population with severe mental disorders. Participants are encourage to adopt regular physical activity habits to improve quality of life, physical and mental health (34). It is a community-based research project offering weekly free PA sessions for persons with schizophrenia, bipolar disorders and depression. Exercise sessions are offered 1-3 times per week with an average duration of 60 minutes in an inclusive university setting (35).

The assessment of most outcome variables will be conducted in an objective manner, resulting in a decreased probability of encountering errors in measurement or misclassification. Furthermore, the uniformity of the intervention site among all participants will help mitigate any potential bias. In addition, this program will take into account the specificities of each participant, without prejudicing them or the program. We will use state-of-the-art technologies such as the Garmin Vívosmart 4 smartwatch to monitor the participants' heart rate. Moreover, this program will have a longer intervention period than usually observed. The type of exercise selected for the intervention program aims to enable participants to practice PA in an autonomous way (i.e., alone) and with no costs. In addition, PA sessions will also have individual goals, which can have a positive impact on participants, both mentally and physically, and thus improve their quality of life. Our results will provide the necessary information and help strengthen the current evidence regarding exercise as a complementary approach in promoting healthy living in persons with schizophrenia.

To motivate participants, individual goals will be defined. At the end of each session, participants will be invited to establish new goals or maintain the same ones, as appropriate. Participants will receive feedback throughout the sessions to improve performance, attendance and will be invited to share difficulties or other issues related with the intervention. During the follow-up period, participants will be encouraging to do frequent exercise without supervision. The follow-up period will coincide with the summer holiday break.

It is important to acknowledge the existence of specific barriers or limitations associated with this study. Firstly, we foresee a potential sample with several related comorbidities. Secondly, participants tend to adopt sedentary behaviours, increasing the difficulties in the whole process. Based on the differences in participants' baseline characteristics, a less correct interpretation of the outcomes may occur, making it difficult to generalise the results. Despite including participants who are part of the “Mental Health on the Move” project and others who are inactive, we cannot exclude the possibility that the participants involved in the study were more prone to healthy lifestyle behaviours. Moreover, the planning of this program had to be changed and adapted, as the recruitment started at the time of COVID-19 pandemic. The participants were conveniently selected and each participant chose the group in which they wanted to be included. Some participants were afraid of the pandemic situation and showed reluctance to participate. The pandemics delayed and imposed logistical difficulties in the recruitment process and afterwards.

The authors report no conflicts of interest. The Research Centre on Physical Activity Health and Leisure (CIAFEL) is supported by FCT UID/DTP/00617/2020.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Acknowledgements

The authors would like to thank to all participating psychiatric centers: (1) Associação Nova Aurora de Reabilitação Psicossocial (ANARP), Porto, Portugal; (2) Psychiatric Department of Hospital São João, Porto, Portugal; (3) Associação dos Familiares, Utentes e Amigos do Hospital Magalhães Lemos, Matosinhos, Portugal. The collaboration of all participants and clinical staff from the multi-centers was crucial for the successfully implementation of the exercise program. The authors also would like to acknowledge the support of Instituto Português do Desporto e Juventude (IPDJ) – Programa nacional do Desporto para Todos to the community project “Mental Health on the Move” where the present study was developed.

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No competing interests reported.

Scheduleofstudyprotocol.xlsx

Effects of an outdoor exercise program in persons with schizophrenia: Study protocol

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Abstract

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Background

Methods and analysis

Discussion

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References

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