Effectiveness of Exercise Training on Mental Health, Physical Activity Level and Social Participation in People Living with HIV/AIDS: A Systematic Review and Meta-Analysis

Background: Exercise training may increase physical activity(PA) level, improve social participation and mental health in people living with HIV/AIDS(PLWHA). Thus, a systematic review was conducted to answer the review question: what is the effectiveness of physical exercise training on mental health, physical activity level and social participation in PLWHA? Method: Eight – were systematically searched from 1990 till 2019. This review includes only studies published in English language, on adults (>18years) and are either on HAART/HAART-naïve; only RCTs that gave exercise intervention and assessed mental health, physical activity level and social participation on HIV/AIDS patients. The primary outcomes were mental health, PA level and social participation, while the secondary outcomes included psychological disorders. Results: Meta-analysis of the ve (out of seven) included studies for depression that met the inclusion criteria (n=346 participants) comprising males/females aged ≥ 18 years, show a signicant overall effect (SMD=-0.89,[95%CI:-1.77,-0.01],Z=1.97,p=0.05) of exercise compared to the control group at post-intervention. However, statistical heterogeneity was high (I2=91%,X2=53.14,df=5,p<0.00001). The removal of two papers during sensitivity analysis for missing data/baseline differences showed a large signicant effect (SMD=-1.01,[95%CI:-1.45,-0.57],Z=4.48,p=<0.00001). The statistical heterogeneity was low (I2=39%,X2=4.94,df=3,p=0.18). The results demonstrate a signicant trend towards a decrease in depressive symptoms for participants in the exercise compared to no exercise group; aerobic exercise compared to normal routine activity group; aerobic and resistance exercise compared to other control groups. Narrative synthesis demonstrates the benecial effects of exercise training on outcome measures: anxiety and cognitive function, apart from other psychological benets. There was limited and no RCTs on the effects of exercise on physical activity level and social participation, respectively. Conclusion: Combined exercise (Aerobic exercise+Strength training; 80mins/session; 3X/week for 12weeks.) + routine counselling OR Aerobic exercise training+counselling 40mins per session; 3X/week for 6weeks OR Combined exercise: Aerobic and Resistance exercise training 50mins/session; 2X/week for 6weeks OR Combined exercise: Aerobic and Resistance exercise training 60mins/session; 3X/week for 24weeks OR Aerobic exercise training 60mins per session; 3X per week for 12weeks may improve mood disorders while therapeutic exercise(2X per week for 6weeks) may improve psychological wellbeing. received behavioural disease counselling. Anxiety was determined as a subscale of the GHQ-28 scale. The study reported that there were no benecial effects of a 12-week exercise programme on anxiety in the exercise group compared to the control group (p = 0.07). One study conducted in the USA [36] involved 49 (asymptomatic = 63%, Mild symptom = 10%, Severe symptom AIDS patients = 25%, Missing report on status =2%) participants (age range 18 and older) that included 37 (75.51%) males and 12 (24.49%) females. The experimental group received a combination of aerobic and resistance exercise training (aerobic exercise: 30 minutes on a treadmill at 50-70% MHR; 2x per week + Resistance exercise: upper and lower-body resistance training: 1 set of 12 repetitions each on plate-loaded Hammer Strength machines; upper anterior and posterior legs on Life Circuit machines; free weights, and the biceps brachii and deltoids using free weights) for 20 mins x 3 = 60 mins, 2x per week while the control group were engaged in sedentary activity. Stress was determined using the Symptom Distress Scale, and the Perceived Stress Scale. The study reported that the perceived stress (measured with the PSS) signicantly increased in the sedentary control group but not the exercise group. The study suggested that 6 weeks of structured combination exercise training may have a protective effect and thus prevented a similar worsening trend in the perceived stress in the exercise group as evident in the control group.

Mental health is not only the absence of psychopathology but the emotional, psychological and social well-being of an individual or group [25][26][27], and maybe boosted by interventions that improve any of these aspects of which physical exercises have been recommended. Invariably, physical exercise could be considered as a self-management strategy that may be deployed as a rehabilitation intervention to address disability in patients with HIV and improve or sustain the (mental) health of PLWHA [28] but requires evidence of e cacy to guide practice. Therefore, this review aimed to determine the effectiveness of physical exercise training on mental health, physical activity level and social participation in PLWHA. The review question is -What is the effectiveness of physical exercise training on mental health, physical activity level and social participation in PLWHA? To answer the review question, speci c review objectives sought to determine the effectiveness of physical exercises in improving psychological disorders, physical activity and social participation.

Methods
This systematic review was registered according to the International platform of registered systematic review and meta-analysis protocols (INPLASY register) on 9 April 2020 (registration number: INPLASY202040048).

Eligibility Criteria
Eligibility criteria considered for selecting studies in the review include: Inclusion criteria: Type of studies: This review includes only original studies published in the English language, in peer-review journals and conferences proceedings. Only studies based on randomised control trials (RCTs) design were included in the review when the following objectives were evaluated effects of exercise training on mental health, physical activity level and social participation in PLWH.
Participants: This review included only RCTs of the effectiveness of physical exercise training in PLWHA, who are adults (>18 years) and are either on HAART or HAART-naïve. Though no speci c limitation on the setting of the studies was considered, nevertheless, the included studies were mainly carried out in clinics, health centres, hospitals or community care settings.
Intervention: RCTs of physical exercise intervention for PLWHA were included in the review, which was not restricted to speci ed dosage, form, intensity, frequency and duration of intervention or follow-up period after the intervention. The exercise intervention may be hospital-based, community-based or home-based, and the exercise type may be aerobic, resistance exercise or a combination of both. Similarly, RCTs of resistance exercise intervention were not limited to weight training, isometric and isotonic strengthening exercise in PLWHA.
Control: This review includes studies that compared the effectiveness of physical exercise training on mental health, physical activity level and social participation to any other treatment options, such as usual prophylactic care, counselling or no treatment, in PLWHA.
Outcomes: The outcomes of interest in this review include mental health, physical activity level and social participation as primary outcomes and psychological disorders as a secondary outcome. Studies were included regardless of whether an outcome of interest was accounted for as a primary or secondary outcome in the rst article, so far as a clear analysis was carried out for each outcome. All outcome variables were collated as they were accounted for in individual studies, and the original description in those individual studies was not modi ed. Clinical results, detailed by individual studies were analysed and graded.

Exclusion criteria:
Studies without an exercise or physical activity intervention component.
Narratives review synthesis, systematic reviews, opinion papers, letters and any publication without primary data and/or explicit description of the methods.
Duplicate publications from the same study, the most recent or most comprehensive publication were used.

Information sources and search strategy
An extensive search strategy to identify eligible studies was done in two stages including; (i) the search of the bibliographic database and grey literature, and (ii) the selection of studies for inclusion based on eligibility criteria. Searches involved several combinations of search terms from medical subject headings (MeSH) and keywords with a combination of Boolean logic in the title, abstract and text for the population, intervention, control and outcomes, rst in a pilot search to establish the sensitivity of search strategy. This strategy was used differently for the three selected study outcomes. PubMed search strategy is shown in Appendix I. This strategy was modi ed to the syntax and subject heading of other databases. Studies were searched in PubMed, Emcare, Cochrane Library, Embase, CINAHL, AMED, PsycINFO and MEDLINE. Additional searches were made from the reference list of identi ed studies. This procedure was by the guidelines of the Cochrane Handbook for Systematic Reviews [29], and advice for Health Care Review by the Centre for Reviews and Dissemination [30].

Study record and Data management
The literature search result was exported into RefWorks TM to check for duplication of studies. Bibliographic records were exported from RefWorks TM into Microsoft Excel 2007 to facilitate the management and selection of articles for inclusion into the study based on speci c eligibility criteria.

Selection Process
The screening was performed in two phases. The initial screening was conducted based on the title and abstract by V.U. (reviewer 1) to identify articles that met the eligibility criteria. I.F.O (reviewer 2) independently cross-checked the initial screening results. The two reviewers then read through the full text of selected studies for further screening, using the eligibility criteria. Differences in opinions at any stage regarding inclusion or exclusion were resolved by discussion and re ection or in consultation with D.I.S (reviewer 3) when needed to remove assessor bias. The reasons for excluding studies were adequately documented, and details of the study selection process are presented in Figure 1.

Data collection Processes
Quality appraisal of included studies: The PEDro scale for quality appraisal of clinical trials was used to appraise the quality and the risk of bias in the included studies. The PEDro scale is based on the Delphi list developed by Verhagen and colleagues at the Department of Epidemiology, the University of Maastricht [31]. The scale consists of a checklist of 10 items/questions, scored "yes" or "no" on the internal validity and statistical information provided in the study. The quality of the study was classi ed into -poor (≤3), fair/moderate quality (4)(5), and high quality (6-10). Poor quality study means that the study has a high risk of bias, while high-quality study means the study has a low risk of bias. Two reviewers made judgments regarding the risk of bias independent of each other. Areas of differences were resolved by discussion and re ection, or in consultation with the third reviewer. Appraisal of the quality of the included studies was carried out after study selection was completed and during data extraction and synthesis. The strength of evidence for this review was further reported.
Data Item: The variables for which data from selected studies were collected include -authors reference, participants' characteristics (including age range, gender, sample size), study sample size (also groups sample size where available), components of the intervention, the intervention setting, who delivered the intervention, duration of intervention and follow-up (where available), control, attrition rate, outcome(s) assessed, the outcome(s) measurement methods/techniques and summary of results, conclusions and funding sources.

Data synthesis and assessment of heterogeneity
The review question of the effectiveness of physical exercise training on mental health, physical activity level and social participation in PLWHA was answered. In doing this, all quantitative study outcomes which analyzed the effectiveness of these interventions were presented, considered and combined in a proof table. The appropriate statistical techniques were used for each study outcome. For continuous variables, weighted mean differences were applied when outcomes are uniform or standardised mean difference (SMD) when different outcomes are used with a 95% con dence interval. SMDs were calculated using means, standard differences, and sample sizes post-intervention (post-treatment effect sizes) according to the standard analysis procedure in the Cochrane meta-analyses.
A pre-post analysis was conducted for the main outcomes, by subtracting the post-intervention means from the pre-intervention means between all groups to determine the differences (a new mean). SMD ranges were interpreted as follows: small = 0.00-0.39, moderate = 0.40-0.70, and large = >0.70 [32]. Alpha was set at p<0.05., For dichotomous variables, the risk ratio was applied with 95% CI. Characteristics of the retained studies were sorted by year of publication and presented in a tabular form providing information relating to authors' references, sample size, age, setting, data collection format, outcomes, components of the intervention, component of the control, format and provider of the intervention, intervention and follow-up periods, and results. This review also includes a meta-analysis to nd pooled effect sizes across studies, using a random-effects model relying on the level of heterogeneity of intervention effects.
Heterogeneity was assessed using the Cochrane's χ 2 test (10% signi cance level) and Higgins I 2 for which values of 25%, >25 -75%, and >75% shows low, medium and high heterogeneity respectively as stipulated by the guidance in the Cochrane Handbook for Systemic Reviews of Interventions [30]. Investigation and presentation of outcomes were made using the primary outcome. Studies with homogenous characteristics in terms of design, intervention, and comparator(s) were pooled together for meta-analysis using a random-effects model. Heterogeneous studies were interpreted using narrative synthesis following the recommendation of the Centre for Reviews and Dissemination to explore the relationship and ndings between and within the included studies [29]Sensitivity analysis was done to decide the impacts of studies with a high risk of bias on the general outcomes with and without these studies.

Rating quality of evidence and strength of recommendation
The quality of evidence of the studies was evaluated using the Grading of Recommendations Assessment Development and Evaluation (GRADE) approach [33]. The GRADE approach evaluates consistency, design, directness, precision, publication bias and studies limitations. The studies in this review were graded as having a high risk of bias or low risk of bias, and then again individual evidence statement was graded from 'High Quality' to 'Very Low Quality' according to the criteria.

Search result
Searches were carried out sequentially using the three primary outcomes (namely mental health, physical activity and social participation) in the search strategy. The initial search yielded 795 potential citations of which seven publications were considered eligible to be included in the review. Using the primary outcome measured in each study, mental health included seven publications [23,[34][35][36][37][38] while physical activity included only one publication [34]. However, no study reported the effect of exercise intervention on social participation.

Reasons for exclusion
Reasons for exclusion of studies following full-text screening included: studies had a control group that was exercising (n= 1), pre-test -post-test study design with no control group (n =1), Non-Randomized control trials (n=3), studies with missing data (n=2), studies with a non-human population (n=1), studies that did not have outcome measure of interest (n=1) (Figure 2).
Included studies Table 1 provides the study characteristics of the seven included studies in this review, and further details are provided below - has a "usual activity" control, Aweto, Aiyegbusi [35] engaged "only counselling" control and a study [34] maintained a "no intervention" control. For therapeutic exercises: Daniels and Van Niekerk [39] utilised a "read prescribed materials" control.

Physical activity Level
Only one study [34] reported the effect of an exercise intervention on physical activity level. McDermott, Zaporojan [34] utilised supervised aerobic exercises only and maintained a "no intervention" control.

Participants of the included studies
Mental health A total of 346 participants were included in this review Participants were within the age range of 18 years and above, and the majority (222 or 64.16%) had asymptomatic HIV (Stage one) based on the WHO clinical staging for HIV/AIDS [40], The location of studies varied as two studies were located in the USA [36, 38] and one study each in Nigeria [35], Iran [23], Australia [37], South Africa [39] and Ireland [34] (Table 1) Physical activity Level Only one RCT [34] was included and involved 11 participants with asymptomatic HIV patients, aged 18-65. The location of the study was Ireland. Quality appraisal and risk of bias assessment

Outcome of intervention
The risk of bias within the included studies is provided in    Table 4 Outcome values for PA level Eligibility criteria The authors from the seven (7) studies reported on the Inclusion and Exclusion criteria used in recruiting and screening participants for their respective studies. Hence the low risk of bias was evident in the whole studies.

Random allocation
Seven studies reported on using the randomization process to allocate their eligible participants to the different groups. Thus, they are free of selective reporting bias.

Concealment of allocation
There was lack of concealed allocation, detection bias for not reporting or providing enough information about blinding of the assessor and no Intention to treat analysis In six [23, 34-36, 38, 39].

Baseline comparability
There are no baseline differences in the characteristics of the measured variables among the included participants in all the studies and are free of nonequivalence bias.

Bias on blinding
Only two studies reported on the assessor and personnel blinding [37,38] and were thus judged to have a low risk of bias in this regard.
The bias of outcome measurement from <85% of initial participants (incomplete outcome data) Three (42.9%) studies reported adequate follow-up [34,37,39] (Table 3). Overall, 84 out of 346 participants at baseline withdrew from the included studies accounting for ~24% of the total number of participants. Withdrawal rates within individual studies ranged from 12.5% [37] to 47.31% [36] (Table 1). However, a high risk of attrition bias exists as ve [23,[34][35][36][37][38] of the seven included studies (71.43%) reported withdrawal rates of >15%. However, one study [39] reported that no participant withdrew from the study. Two (28.57%) studies have a low risk of incomplete outcome bias by having a retention rate ranging from 87.5% to 100% due to low attrition [37,39]. The withdrawal rate between comparison groups was similar in most groups. Almost all the included studies mentioned participant who did not comply with their exercise intervention or withdrew from the study. Only two authors [34,37] reported information on adherence to the exercise intervention. Adherence ranged from 60% [34] to 81% [38].

Narrative Synthesis
A narrative synthesis was done by determining how the studies are related. Thus, the key concepts were itemised, compared and contrasted translating the studies into one another and synthesising the translations to identify concepts which go beyond individual accounts and was used to produce an interpretation of the effects of physical exercise on mental health, physical activity level and social participation.

Physical activity level
One study [34] which assessed Physical activity level, and which was not included for meta-analysis, evaluated the effectiveness of aerobic exercise in improving the physical activity level in 11 HAART treated HIV-infected patients (age range 18 -65 years). The study was conducted in Ireland for 16 weeks whereby ve participants (age= 43 ± 4 years) were allocated to the exercise group and six participants (age = 44 ± 11 years) to the control group. One participant from each group did not complete the study. The experimental group received aerobic training (treadmill, cycle ergometer and cross trainer) of equal duration per supervised session) for 31-52 minutes per session at 40-45% HRR, three times per week, while the control group (n=7) received no treatment. Physical activity level was determined as sedentary/light/moderate/vigorous physical activity (hour per week) using the Actigraph GT3X+ Tri-Axis Accelerometer. The study reported no signi cant change in the physical activity level in the exercise group compared to the control group (p>0.05) but provided no information on the effect size of the intervention.

Mental health
Seven studies [23,[34][35][36][37][38][39], reported the effectiveness of exercise training on mental health. There are variations in the outcome tools that were used to assess mental health across individual studies. Three moderate quality studies [23,34,35,39], and one high-quality study [37] reported a signi cant effect of exercise training on mental health in the intervention group compared to the control group. One moderate quality study [34] did not nd a signi cant effect of exercise training on mental health in the intervention group compared to the control group in the three different outcome tools that were used to measure mental health. One high-quality study [38], reported a signi cant effect of exercise training on mental health in the intervention group compared to the control group in one (CES-D) out of the three different outcome tools that were used. Also, one low-quality study [36] reported a signi cant effect of exercise on mental health in one (POMS) out of the three different outcome tools that were used in the intervention group compared to the control group. Only one [39] out of the seven studies reported the effect size for mental health in the intervention group compared to the control group.

Sub-component analysis for mental health Anxiety/Stress
Two studies [23,36] assessed anxiety and were not included for meta-analysis. One study [23]

Cognitive function
Two studies [34,37] assessed cognition which was not included for meta-analysis. One moderate quality study [34]  A high-quality study [37]

Meta-analyses -Effects of interventions
This review conducted one meta-analysis for studies on depression (mental health). Three of the included studies [23,36,39] compared combined exercises (aerobic exercise, and resistance training) with no exercise. Two studies [35,38] compared aerobic exercise with normal/usual routine activity.

Heterogeneity
Heterogeneity (p<0.01) was evident in the main meta-analysis which could be as a result of the differences in gender, location, variation in the type and dose of exercise intervention administered, measurement tools, and the number of participants (6 -30 participants) across the studies. Sensitivity analysis was carried out with only those categories greater than two studies since heterogeneity exists in the meta-analysis. Thus, the results and reasons include:

Mental Health (Depression)
Five [23,35,36,38,39] of the seven included studies assessed depression as an outcome for mental health. For these ve studies, a large overall standardized mean difference SMD = -0.89, 95%CI: -1.77, -0.01) for mental health in favour of the exercise group was found in the random-effect model for post-intervention values. There was a signi cant overall effect (Z = 1.97, p = 0.05) of exercise compared to the control group at post-intervention. However, statistical heterogeneity was high (I 2 = 91%, X 2 = 53.14, df = 5, p<0.00001) (forest plot- Figure 2). The results demonstrate a signi cant trend towards a decrease in depressive symptoms for participants in the exercise compared to no exercise group; aerobic exercise compared to normal routine activity group; aerobic and resistance exercise compared to other control groups. Measuring tools used from the included studies were: GHQ-28; BDI; MOCA global score; Trail marking Test A; Trail marking Test B; SDS; POMS; PSS; GS-ES; CES-D. (Table 1).

Sensitivity analysis
After the main meta-analysis, the rst sensitivity analysis was done for depression that excluded the trial by Daniels and Van Niekerk [39] because of missing data about the prescribed exercise minutes per session and/or sessions per week, and the requirement that exercises are self-administered as a home programme. A large overall signi cant effect was found (SMD= -1.23 [95% CI: -1.77, -0.69], Z = 12.06 (p = < 0.00001). However, statistical heterogeneity was evident (I 2 = 67%, X 2 = 12.06, df = 4, p= 0.02) (forest plot- Figure 3).
A second sensitivity analysis was also conducted for depression and excluded two clinical trials in which the control and exercise groups appeared to be non- Grade Rating: The effect estimate demonstrates that physical exercise has an overall signi cant effect of 0.89 points (95% CI: -1.77, -0.00, p<0.05) for depression due to mental health when comparing exercise group to controls, and which can be accepted as moderate evidence. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it may be substantially different. This outcome was downgraded from high to moderate GRADE quality of evidence, because of the inability of authors to conceal allocation in the assignment of participants to experimental and control groups.

Discussion
No study fully measured all the aspects of mental health, instead, they only selected and measured three aspects of mental health such as anxiety/mental distress [36], depression [23,35,36,38,39], cognitive disorder [34], and psychological disorder [23]. These studies suggest that it is also possible that other aspects of mental health may be improved by exercises in PLWHA and corroborates the ndings of other studies [41,42].
Meta-analysis for depression included ve studies [23,35,36,38,39], cognitive disorder [34] and presents overall evidence that exercise training was effective in ameliorating the symptoms of depression in PLWHA. Thus, there is evidence that aerobic exercises or combinational (aerobic + resistance) exercises performed 2-3 times/week, at 40 -60 minutes per session, and for between 6-24 weeks, effectively ameliorated the symptoms of depression in PLWHA. The evidence grade rating of this effect is high and therefore, may have signi cant clinical importance. The ndings of this study agree with evidence from other studies [1,15,43,44], which reported on the effectiveness of physical exercises in ameliorating depression in PLWHA. Previous studies provided evidence where both aerobic and resistance exercise have independent and combined positive effects on various indicators of mental health in people living with HIV [41]. Similarly, an earlier systematic review [15] found evidence that performing an aerobic exercise or a combination of aerobic and resistive exercise at least three times per week for at least ve weeks can lead to improvements in symptoms of depression for adults with HIV. Also, four earlier systematic reviews [10,[45][46][47] restated the effectiveness of physical exercise on psychological outcomes, such as depression [46], and health-related quality of life [45]. It was reported that aerobic exercises particularly, improve the quality of life, hope, desire to continue living, and depression [45,47]. A signi cant improvement on the Pro le of Mood States Depression-Dejection subscale was found with aerobic exercise intervention (MD = −7.68 points, 95% CI [−13.47, −1.90], n = 65, I 2 = 94% [47]. Another systematic review by Gomes Neto, Ogalha [45] indicates that combined (aerobic and progressive resistance) exercises can improve healthrelated quality of life. A recent systematic review [43] show that exercise has a large effect on depression ( = 8, p= 0.02), and weakens our con dence in the estimate of effect. Importantly, their ndings cannot be strictly attributed to the effects of physical exercises alone, unlike this study, which included only studies that investigated conventional exercises alone.
A recent review paper [49] highlights the physiological basis for the observed bene cial effects of exercises on mental health. The review highlights that aerobic exercise could increase the size and function of important brain regions, such as the hippocampus, and thus may improve the brain control responses to stress, reduce in ammation, and increase resistance to oxidative stress. All of which may likely contribute to the bene ts of exercise on mental health and cognition. Other aspects of mental health (cognition and anxiety) appraised in the narrative synthesis showed a similar trend, through a meta-analysis was not conducted because of a paucity of RCTs in the literature that studied these aspects of mental health in PLWHA. It was, however, observed that most of the studies (four studies) reported a signi cant effect of exercises on mental health in the intervention group compared to the control group.

Physical Activity Level
Only one moderate quality study [34] reported the effect of an exercise intervention on physical activity level and did not nd any signi cant difference (p >0.05) between the groups. It assessed the physical activity level with Actigraph GT3X+Tri Axis Accelerometer. However, the sample size is small, and there is no report regarding the effect size to estimate the clinical signi cance of their ndings.

Social Participation
No study reported the effectiveness of exercise training on social participation in PLWHA. Thus, there is a great need for future research studies to evaluate the effectiveness of exercise training on social participation in PLWHA. This is because several studies [50][51][52][53] have identi ed a link between physical activity pro le and social participation probably due to the effects of physical activity on mental health, especially mood [54][55][56]. However, a causal relationship between these variables have not been established in PLWHA and needs to be investigated. This agrees with the view of a previous author that HIV and rehabilitation research should also focus on social participation [28]. This is important in this population considering that social stigmatization is still a big problem facing PLWHA in different countries of the world, and which may lead to low self-esteem, mood disorders, and withdrawal from social activities [57] thereby resulting in a sedentary lifestyle. The added effects of declining ambulatory function, which is often restricted with polypharmacy and rise in complications associated with HIV infection [58] may add to the lack of physical activity and restriction in participation in community-based social activities.
The resulting multi-system (neurological, musculoskeletal, cardiopulmonary and metabolic) dysfunction may impair walking function, as well as the quality of life [59]. Limited social participation may also be related to a feeling of low self-esteem or rejection [60]. Therefore, any intervention that may improve mental health by improving mood, and self-esteem in PLWHA, may also improve their physical functioning and likewise social participation.

Conclusion
Implications for practice . Importantly, mood disorders, which is common in HIV conditions due to the infection and side effects of the medication (HAART) in patients, have also been linked to poor adherence to medications and consequently, poor health outcomes [1][2][3][4][5][6]. If physical activity/exercises ameliorate symptoms of mood disorders (depression), it may also improve adherence to medication and likewise other related health outcomes. Therefore, public health policies and initiatives designed to increase participation in exercises may have the potential to improve mental health and general wellbeing among PLWHA.
There were notable potential sources of bias such as incomplete outcome reporting, small sample size, short intervention duration, blinding of therapists and assessors, on which basis we downgraded our con dence in the estimate of effect and therefore further rigorous and high-quality studies are required to guide practice. Meanwhile, the paucity of RCTs on the effectiveness of exercise on other aspects of mental health (apart from depression), physical activity level and social participation made it di cult to form a scienti c opinion that will guide practice in these areas. Consequently, there is a need for more rigorous studies in these areas considering the health bene ts that the PLWHA nay derive from such interventions if proven to be of therapeutic value.

Implications for Research
Most studies that evaluated the effectiveness of exercises on mental health and physical activity level were underpowered to detect the difference in mean between the intervention and control groups. Most of them failed to provide information on the adherence rate to estimate its effect on sample size. These weaknesses may affect the validity of the ndings. For depression, the heterogeneity of the primary meta-analysis was high and highlights some issues that need to be addressed in future studies. For instance, the sensitivity analysis excluded two studies for i.) missing data about the prescribed exercise minutes per session and/or sessions per week, and the requirement that exercises are self-administered as a home programme [39], and ii.) the non-equivalence of the control and exercise groups before the trials due to large differences in the baseline values of depression [36,39]. The exclusion of these studies resulted in a low heterogeneity in the meta-analysis of the remaining studies, which strengthens the view that the aws in the excluded studies distorted the homogeneity of the data. These problems are possibly related to aws in trials design/documentation and implementation of randomisation which should be addressed in future studies.
Furthermore, the only study [34] on the effectiveness of physical exercises on physical activity level found no effect but was underpowered. Invariably, there is a possibility that the true effects of exercise training on physical activity level in PLWHA were underestimated in the study. Also, most behavioural intervention studies assessing the effects of physical activity level usually incorporate a behaviour change model.
[62] This helps in developing lifestyle promotion strategies to accumulate physical activity as well as appropriate walking plans for enhancing, motivating, and overcoming barriers to physical activity.
Importantly, such behavioural intervention studies are driven by speci ed behaviour change theories/models aimed at identifying modi able predictors of subjects' behaviours towards physical activity [63]. McDermott, Zaporojan [34] did not ful l all these requirements, and may partly explain why their study was unable to nd a signi cant difference in the physical activity level when the intervention group is compared to the control group. Therefore, there is a need for future studies to address these gaps to enhance the validity of their ndings.

Limitations
There are several limitations to this study. Apart from the fact that various outcome tools with different validity and reliability values were used to measure mental health in the included studies, mental health is somewhat subjective and therefore di cult to objectively/accurately measure. Besides, the self-reported psychometric instruments used in data collection for the included studies are prone to recall bias. Also, no study measured all aspects of mental health, rather some aspects of mental health such as perceived stress [36], depression [35,38,39], mood [36, 38], cognitive disorder [34], mental distress [36] and psychological disorder [23] were measured. Considering these limitations, there is a need to develop more encompassing outcome measurement tools that will assess most, if not all aspects of mental health; and which should be valid, and reliable to guide practice. However, the application of the standard mean difference seemed to address these limitations and provided a good comparative basis to evaluate the effectiveness of exercise intervention on variables of interest across the studies. Availability of data and materials

List Of Abbreviations
The datasets supporting the conclusions of this article are available in the institutional University of Nigeria repository and will be made easily available on request when required.   Forest plot for mental health: sensitivity analysis of three studies

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