A positive psychology approach to mental health and well-being entails the intentional promotion of psychological strengths as opposed to treating symptoms of mental illness (Wissing, 2022). Within the positive psychology framework, well-being is defined in two spheres, which concerns feeling (hedonic) well and functioning (eudaimonic) well (Grant & McGhee, 2020), and it is most comprehensively studied by considering both positive and negative indicators (Donaldson et al., 2019). In line with this, Keyes (2002) conceptualises mental health as a multidimensional concept that encompasses emotional, psychological, and social functioning. A state of flourishing, which entails the presence of mental health and the absence of mental ill-health, has important implications in workplace contexts (Grant & McGhee, 2020; Spreitzer & Hwang, 2019). It links to positive organisational outcomes, such as greater productivity, work engagement and job satisfaction (Haddon, 2018; Moller & Rothmann, 2019).

The well-being of university employees in the South African context is concerning. Stress in higher education institutions (HEIs) is caused by a variety of factors, such as student protests, high workloads, time pressure, job insecurity, lack of role clarity and poor teamwork (Jasson et al., 2022; Poalses & Bezuidenhout, 2018). This has negative implications in terms of employee morale and organisational effectiveness, which calls for well-being intervention in this context (Mathews et al., 2022).

Advocates have pushed for more strengths-based approaches in workplace contexts (Marx, 2017; Stelzner & Schutte, 2016), yet a scoping review of positive psychology intervention (PPI) studies on the African continent indicated a paucity of workplace PPI studies in the South African context, particularly in HEIs (Guse, 2022). Promising results were found in a qualitative exploration of a yoga-based PPI aimed at promoting employee well-being at a selected South African HEI (Meiring et al., 2025). The present study was exploratory in nature. Quantitative data on the impact of the yoga-based PPI were obtained at various time points during and after the intervention. Validated well-being scales were used to assess positive and negative indicators of employee well-being. It was expected that participation in the PPI would improve mental health (H1), enhance work engagement (H2), and increase positive affect (H3). A decrease in negative affect (H4) and perceived stress (H5) was anticipated.

Positive psychology interventions aim to promote well-being among non-clinical populations and are regarded as a strengths-based approach to wellness, aimed at enhancing positive feelings, cognitions, and behaviours (Hendriks et al., 2020; Lomas et al., 2015). With a focus on building strengths and promoting aspects related to well-being, workplace PPIs do not exclusively cater to distressed or troubled employees, which consequently removes the stigma of programme participation that is commonly associated with the involvement in reactive employee wellness initiatives (Dobson et al., 2019).

A meta-analysis by Donaldson et al. (2019) showed that workplace PPI is as effective for targeting aspects detrimental to well-being as it is for promoting desirable well-being indicators. Further supporting this, a 6-week in-person workplace programme including yoga, physical activity and mindfulness meditation significantly reduced perceived stress and negative affect at post-intervention and at 12-month follow-up, while increasing happiness and positive affect at post-intervention and through 12-month follow-up (De Bruin et al., 2020). A recent systematic review of mindfulness-based stress reduction and gratitude PPIs among healthcare workers demonstrated measurable improvement in positive indicators and reduction in negative indicators, including subjective well-being as well as stress and burnout from interventions ranging between 15 days and 6 months (Townsley et al., 2023). A randomised placebo-controlled field experiment investigating the effects of an online intervention for teachers showed that PPI can enhance aspects related to employee engagement (Dreer, 2020). In contrast, findings from Ouweneel et al. (2013) did not show a significant increase in work engagement following an 8-week online PPI. Meta-analytic findings from 22 studies by Donaldson et al. (2019) showed that workplace PPIs had a small-to-moderate effect on positive and negative well-being indicators. They noted that the delivery method (individual, group and online) played a role in terms of the impact on desirable and undesirable work outcomes.

Considering factors that could influence the effectiveness of workplace PPIs, Koydemir et al. (2020) suggest that face-to-face interventions may have a greater impact than interventions implemented using technology. De Bruin et al. (2020) underscore the value of offering programmes on-site to enhance adherence through regular attendance. In their model for sustainable happiness, Lyubomirsky et al. (2005) identify optimal timing, person-activity fit, variety of activity, sustained effort, and positive habits as key factors essential for successful well-being outcomes through intentional activity. Evidence also suggests that interventions of longer duration might have stronger effects, as they allow time to form new habits and incorporate them into everyday life (Khosla & Misra, 2022; Koydemir et al., 2020). Finally, using a multi-component PPI ensures that wellness is approached holistically and that both hedonic and eudaimonic aspects of well-being are targeted with a single intervention (Hendriks et al., 2020; Khosla & Misra, 2022). Feasibility studies in a real-world context must contend with methodological challenges such as self-selection, high attrition and small sample sizes (e.g. Osman et al., 2021). In the absence of a control group, the present study explored the effect of the well-being intervention in terms of multiple positive and negative outcome indicators measured repeatedly.

Yoga is considered a physical, psychological, and spiritual science for the holistic growth of mind, body and soul (Bista & Bista, 2023). Lasting wellness promotion is at the heart of this ancient system, which entails numerous components that can be used to heal, integrate, balance and transcend suffering (Khosla & Misra, 2022; Siegel et al., 2016). Yoga teaches human beings the power to reveal their positive qualities and to reduce their deficiencies, similar to the focus of positive psychology (Akdeniz & Kaştan, 2023). In the classical text by Patanjali, yoga is systematised into eight limbs concerning social ethics, personal discipline, body postures, breathing practices, withdrawal of the senses, focussed concentration, meditation and personal transcendence (Bista & Bista, 2023; Saraswati, 2013a). The current study incorporated these core aspects in a single multi-component PPI with two programme components, theoretical and physical, thus going beyond previous work, which commonly focused on the physical aspects of yoga, breathing, relaxation and meditation (Della Valle et al., 2020; Puerto Valencia et al., 2019).

There is limited evidence of multi-component PPIs targeting healthy adults that combine mental, behavioural and physical components (De Bruin et al., 2020; Donaldson et al., 2019; Hendriks et al., 2020). The authors are not aware of any studies that utilised yoga as a multi-component workplace PPI, highlighting the unique contribution of this work. Although results are inconclusive due to limited statistical power, there is evidence that postural yoga can positively impact mental health (Domingues, 2018) and is effective for reducing stress in working adults (Della Valle et al., 2020). Yoga can benefit physical, emotional, psychological and social aspects of well-being (Akdeniz & Kaştan, 2023), qualifying it as a holistic approach to well-being.

A quantitative approach informed the quasi-experimental, repeated measures, within-group design. This formed part of a larger mixed-methods study that explored the effectiveness and feasibility of a 36-week yoga-based PPI (Meiring, 2023).

Ethical clearance was obtained from the University of South Africa College of Human Sciences Research Ethics Committee (2018-CHS-0221). The institution that was approached to partake in the study provided written permission to conduct the study. All procedures were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Arrangements related to the recruitment of participants and the implementation of the programme were made with relevant role players. All employees were invited via an electronic advertisement to partake in the 36-week intervention. Information was provided on the research aim and related research activities, eligibility criteria, and participation expectations. The advertisement was re-published once weekly for 3 weeks, followed by a face-to-face information seminar. Participation was voluntary, and written informed consent was obtained from all individual participants involved in the study. Participants were also required to sign an indemnity form before participating in the physical yoga sessions. All information was kept confidential.

The yoga-based PPI was implemented over 36 weeks, and data were gathered at four different time intervals, namely 0 weeks (baseline), 18 weeks (intervention mid-point), 36 weeks (intervention conclusion), and 48 weeks (12 weeks post-intervention). An online questionnaire was completed by the participants at each point. The questionnaire included a demographic section and measures of mental health and well-being, work engagement, positive and negative affect and perceived stress.

Participants received a link to complete the electronic questionnaire at four time points (0 weeks, 18 weeks, 36 weeks and 48 weeks), and responses were recorded in a password-protected Excel spreadsheet. During data preparation, mean imputation was used to deal with item non-responses found in the four measures (Durrant, 2005; Rässler & Riphahn, 2006). This implies that missing values for a variable are replaced with the mean of observed values for the same variable, thereby maintaining the sample size in instances of item non-response. Microsoft Excel (Microsoft Corp., Redmond, WA, US) and Statistical Package for the Social Sciences (SPSS) version 27 software (IBM Corp., Armonk, NY, US) were used to analyse the data. Descriptive statistics were calculated for the scale and subscale scores. Cronbach’s coefficient alpha was used to determine the internal consistency reliability of the questionnaires. The normality assumption was tested for the Mental Health Continuum Short Form (MHC-SF), the International Positive and Negative Affect Schedule Short Form (I-PANAS-SF), the Utrecht Work Engagement Scale (UWES-9) and the Perceived Stress Scale (PPS-10) using the Shapiro-Wilk test, skewness and kurtosis values, histograms, scatter plots and Q-Q plots. Based on the results, non-parametric inferential statistics, namely the Friedman and Wilcoxon signed-rank tests, were used for the repeated measures analysis. These tests are rank-based and thus less sensitive to outliers and are suitable for data that violate stringent parametric assumptions (Field, 2009).

The Friedman test was suitable to determine differences in indicators between time points for participants who provided data at all relevant times (Field, 2009; Wassermann et al., 2019). It accounts for the statistical error incurred when drawing multiple comparisons. Time 1 and Time 3 (n = 18) were compared to determine changes from the start to the end of the intervention, while Time 1 and Time 4 (n = 12) were compared to determine whether there were lasting effects. Pairwise comparisons with the Dunn-Bonferroni post hoc test were used to further explore significant findings. Significance values were adjusted by the Bonferroni correction for multiple tests. Kendall’s coefficient of concordance (Marshall & Marquier, n.d.) was used to determine the effect sizes, and these were interpreted in terms of Cohen’s guidelines (0.10 = small; 0.30 = medium; 0.50 = large; Field, 2009).

The Wilcoxon signed-rank test was used to further explore the impact of the intervention at each time point (T1 × T2: n = 28; T2 × T3: n = 18; T1 × T3: n = 19; T3 × T4: n = 12). Separately testing the alternative pairs resulted in slightly larger sample sizes; however, running multiple tests of individual pairs also increases the likelihood of a Type I error. The effect size was calculated by dividing the z value by the square root of the number of observations across the two time points. Cohen’s criteria were used to interpret the values. A significance level of 0.05 was used in the study. Two-tailed significance was considered to provide for potential fluctuation in the direction of change between the different time points.

The descriptive statistics for the scale and subscale scores at each data collection point are presented in Table 2. There were outliers in most cases, and the median was regarded as a more accurate measure of central tendency (Field, 2009). Visual inspection of the data showed an increase in the case of the positive indicators from Time 1 to Time 3, and followed by a slight decrease or a plateau from Time 3 to Time 4. In the case of the negative indicators, there was a decrease from Time 1 to Time 4.

Participation in the programme led to significant improvements on emotional well-being, χ² (2, n = 18) = 7.033, p < 0.05 and the vigour component of work engagement χ² (2, n = 18) = 9.781, p < 0.05 when comparing the baseline results with results at the conclusion of the intervention (see Table 3). The Dunn-Bonferroni post hoc tests (Table 4) indicate significant increases between Time 1 and 3 in both cases. The effect size was small in the case of emotional well-being (Kendall’s W = 0.195) and moderate in the case of vigour (Kendall’s W = 0.272).

Negative affect χ² (2, n = 18) = 7.651, p < 0.05 and perceived stress χ² (2, n = 18) = 12.030, p < 0.05 decreased significantly from start to end of the intervention. Post hoc testing showed a significant change between Time 1 and Time 3 for negative affect, and between Time 1 and Time 3 and between Time 2 and Time 3 for perceived stress. The effect size was small in the case of negative affect (Kendall’s W = 0.213) and moderate in the case of perceived stress (Kendall’s W = 0.334).

Time 1 (baseline) and Time 4 (12 weeks post-intervention) were compared to determine whether there were lasting effects. No significant difference was found for any of the scales or subscales (see Table 5).

The impact of the intervention was further explored by considering changes in the scale and subscale scores between the different points of data collection using the Wilcoxon Signed-Ranked Test. The results are reported in Table 6.

The aim of the study was to explore the effectiveness of a yoga-based PPI to promote well-being among employees at a selected South African HEI. It was expected that participation in the PPI would improve mental health (H1), enhance work engagement (H2) and increase positive affect (H3). A decrease in negative affect (H4) and perceived stress (H5) was also anticipated.

The holistic nature of the yoga-based PPI, incorporating both physical practice sessions along with the yama and niyama observances within a single multi-component workplace wellness programme is a unique contribution of the present study. Moreover, the structure and presentation of the 36-week PPI adhered to requirements identified in existing literature as important aspects for programme success, such as long-term duration and on-site and in-person presentation (De Bruin et al., 2020; Khosla & Misra, 2022; Koydemir et al., 2020). The study thus illustrates some of the aspects that need to be considered when planning an optimal long-term strategy to promote employee well-being. It also contributes on a methodological level. Using a repeated-measures design added depth to the analysis of the programme effects on selected well-being indicators, revealing nuances of change over time. The theoretically supported changes in the well-being indicators also reflect positively on the validity of the measurement scales used in this study. Finally, in line with Strijk et al. (2013), this study highlights the importance of high programme adherence as an essential aspect for a positive impact. This would not be possible without organisational support for the intervention programme.

Particular research limitations should be noted when interpreting the reported results. The current study was quasi-experimental in nature, and the possible influence of factors other than programme participation cannot be ruled out (Barns, 2019; Gravetter & Forzano, 2009). However, qualitative reports from participants confirmed that taking part in the programme and using the programme tools enhanced their sense of well-being (Meiring et al., 2025).

Despite on-site access to the intervention, the attrition from week 18 to week 36 and from week 36 to week 48 was substantial. The sample size was consequently small. This compromised the statistical power of the analysis and may have contributed to the non-significant results for some variables (Barns, 2019; Field, 2009). High attrition and small sample sizes are common limitations reported for workplace intervention studies (Keeman et al., 2017; Ouweneel et al., 2013; Strijk et al., 2013) and, specifically, PPIs (Bolier et al., 2013). The decline in programme adherence after the 18-week mid-point could also have led to non-significant results, as commitment has been highlighted as critical for positive impact (Strijk et al., 2013). Bolier et al. (2013) nevertheless:

Moreover, these results cannot be generalised as the non-random sample is not representative of the larger population. It is worth noting that the self-selected sample of interested employees who volunteered for the programme is more reflective of a real-world scenario in which employees voluntarily enrol themselves into workplace wellness programmes. Self-selection also helped ensure person-activity-fit, an important factor for wellness promotion through intentional activity (Khosla & Misra, 2022; Lyubomirsky et al., 2005). Replication of this study in other settings is needed to further determine the programme’s impact on selected outcome variables.