This study is a 10-week secondary school-based intervention and will be evaluated using a randomised controlled trial. Ethics approval has been sought and obtained from an Australian University Human Research Ethics Committee, the New South Wales (NSW) Department of Education, and the Catholic Education Diocese of Parramatta. The study is registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12618001405202). The study protocol was also reviewed externally by school psychologists employed by the NSW Department of Education.
Researchers will conduct baseline assessments at participating schools after the initial recruitment processes. Following baseline assessments and randomisation, the intervention group will receive the intervention after which post-intervention assessment will be conducted. A 12-week post-intervention (follow-up) assessment will also be conducted. The control group will receive the same intervention program after the first post-intervention assessment and will not be measured at follow-up. The design, conduct and reporting of this study will adhere to the Consolidation Standards of Reporting Trials (CONSORT) guidelines for a randomised controlled trial . Participants and caregivers will provide written informed consent.
Sample size calculation
Power calculations were conducted to determine the sample size required to detect changes in mental health related outcomes resulting from martial arts training. Statistical power calculations assumed baseline-post-test expected effect size gains of d = 0.3, and were based on 90% power with alpha levels set at p < 0.05. The minimum completion sample size was calculated as n = 234 (intervention group: n = 117, control group: n = 117). As participant drop-out rates of 20% are common in randomised controlled trials , the maximum proposed sample size was n = 293 (intervention group: n = 147, control group: n = 146).
Recruitment and study participants
To be eligible to participate in the study, schools must be government or catholic secondary schools in NSW, Australia. All eligible schools (n = 140) will be sent an initial email with an invitation to participate in the study. Schools that respond to the initial email will be pooled and receive a follow up call in random order from the project researchers to discuss whether they would like to participate in the study. The first five schools that demonstrate interest will then be recruited into the study.
Inclusion criteria for participation in the study includes: (a) participants are currently enrolled in grades 7 or 8, and (b) participants are within an age range 11–14 years. Exclusion criteria: concurrent martial arts training will exclude participation in the study, however prior experience of martial arts training is not an exclusion criteria. All students at participating schools who meet these criteria will be invited to participate in the study. Participant and caregiver information and consent forms will be provided to students. Two follow-up letters will be sent subsequently at 2 week intervals. Students who respond to the invitation will be pooled and randomly allocated into the study, or not included in the study.
Randomisation into intervention and control group will occur after baseline assessments. A simple computer algorithm will be used to randomly allocate participants into intervention or control groups. This will be performed by a researcher not directly involved in the study. Figure 1 provides a flowchart of the timeline for the study.
The intervention will be delivered in a face to face group format onsite at participating schools. The intervention will be 10 × 50–60 min sessions, once per week for 10 weeks. Each intervention session will include:
Psycho-education – guided group based discussion. Topics include respect, goal-setting, self-concept and self-esteem, courage, resilience, bullying and peer pressure, self-care and caring for others, values, and, optimism and hope;
Warm up – including jogging, star jumps, push ups, and sit ups;
Stretching – including hamstring stretch, triceps stretch, figure four stretch, butterfly stretch, lunging hip flexor stretch, knee to chest stretch, and standing quad stretch; and,
Technical practice – including stances, blocks, punching, and kicking.
Additionally, intervention sessions intermittently include (alternated throughout the program):
Patterns practice – a pattern is a choreographed sequence of movements consisting of combinations of blocks, kicks, and punches performed as though defending against one or more imaginary opponents;
Sparring – based on tai-chi sticking hands exercise (which has been included as an alternative to traditional martial arts sparring); and
Meditation – based on breath focusing exercise.
In the final session the intervention will conclude with a formal martial arts grading where participants will be awarded a yellow belt subject to demonstration of martial arts techniques (stances, blocks, punching, and kicking) and the pattern learnt during the program. While it is desirable for participants to attend all 10 sessions to achieve intervention dose, it is unrealistic to assume all sessions will be attended. Research has suggested that determining an adequate intervention dose in health promotion programmes can be based on level of participation and whether participants did well . In the current study intervention dose will be assumed if participants successfully complete the formal grading and are awarded a yellow belt. It is important to note that aggressive physical contact is not part of the intervention program. The intervention will be delivered by a (1) registered psychologist with minimum 6 years’ experience, and (2) 2nd Dan/level black-belt taekwondo instructor with minimum 5 years’ experience. Materials used during the intervention will include martial arts belts (white and yellow), and martial arts training equipment (for example strike paddles, strike shields).
The intervention development and implementation will be based on a traditional martial arts model, dichotomous health model, and social cognitive theory. Research examining the relationship between the martial arts and mental health has typically used a bipartite model  which distinguishes between traditional and modern martial arts. The intervention is based on a traditional martial arts perspective, which emphasizes the non-aggressive aspects of martial arts including psychological and philosophical development .
The absence of an explicit health model is a significant methodological limitation of previous research examining the mental health outcomes of martial arts training. The dominant models of mental health are based on the homeostatic assumption that normal health reflects the tendency towards a relatively stable equilibrium; and that the dysregulation of homeostatic processes causes ill-health . These models can be defined dichotomously as having a: (1) pathological basis (deficit model) which refers to the presence or absence of disease based symptoms such as depression or anxiety; and (2) wellbeing basis (strengths model) which refers to the presence or absence of beneficial mental health characteristics such as resilience or self-efficacy. While considering both aspects of the mental health continuum, this study was particularly interested in the strengths model and examined the wellbeing characteristics of resilience and self-efficacy.
Social cognitive theory suggests that knowledge can be acquired through the observation of others in the context of social interactions, experiences, and media influences; and explains human behaviour in terms of continuous reciprocal interaction between personal cognitive, behavioural, and environmental influences . The theory is useful for explaining the learning processes in the martial arts, which include: (a) modelling – where learning occurs through the observation of models; (b) outcome expectancies – to learn a modelled behaviour the potential outcome of that behaviour must be understood (for example, the anticipation of rewards or punishment); and (c) self-efficacy – the extent to which an individual believes that they can perform a behaviour required to produce a particular outcome .
The study’s theoretical framework incorporating a traditional martial arts model, dichotomous health model and social cognitive theory facilitates examination of the effects of martial arts training on mental health, ranging from mental health problems to factors associated with wellbeing such as resilience and self-efficacy. Further, the framework may determine the efficacy of martial arts training as an alternative mental health intervention that improves mental health outcomes.
Evaluation of the intervention program will involve a variety of standardised psychometric instruments to report on mental health related outcomes. Instruments include the Strengths and Difficulties Questionnaire (SDQ) , Child and Youth Resilience Measure (CYRM) , and Self-Efficacy Questionnaire for Children (SEQ-C) . All outcome time-points will be examined 1 week pre-intervention, 1 week post-intervention, and 12-week post-intervention (follow-up).
Behavioural and emotional difficulties
The primary outcome measured by the SDQ will be mean total difficulties. Additionally, the SDQ will measure the following secondary outcomes: emotional difficulties, conduct difficulties, hyperactivity difficulties, peer difficulties, and pro-social behaviour.
Total difficulties was selected as a primary outcome as it provides an overview of participants’ psychological problems. The SDQ scale is a commonly used psychometric screening tool recommended for use by the Australian Psychological Society  and has been normed for the Australian population.
The primary outcome measured by the CYRM will be mean total resilience. Additionally, the CYRM will measure the following secondary outcomes: individual capacities and resources, relationships with primary caregivers, and contextual factors.
Resilience was selected as a primary outcome as it is a current focus of research regarding psychological strengths, but has not been examined regarding the effect of martial arts training. The CYRM-28 was used in the study as it efficiently operationalises the theoretical aspects of resilience in a valid and reliable manner, but is shorter than comparable scales (for example the Resilience Scale for Children and Adolescents ).
The primary outcome measured by the SEQ-C will be mean total self-efficacy. Additionally, the SEQ-C will measure the following secondary outcomes: academic self-efficacy, social self-efficacy, and emotional self-efficacy.
Self-efficacy was selected as a primary outcome as this operationalised a relevant component of social cognitive theory, which is important regarding the hypothesised learning processes in the intervention. The SEQ-C was used in the study as it operationalises self-efficacy for adolescents in an educationally relevant context.
Statistical analysis of the primary and secondary outcomes will be conducted using SPSS statistics version 25 (IBM SPSS Statistics, 2017) and alpha levels will be set at p < 0.05.
The collected psychometric test data will be consolidated into subscale variables using factor analysis and the internal consistency of each variable will be examined to determine reliability. Items to be included in the scale variables will be added and computed to create composite scores. Repeated measures univariate analysis of variance (ANOVA), and multivariate analysis of variance (MANOVA) will primarily be used to analyse test data. Ordinal regression will be used to analyse test data based on psychometric measures using a 3-point Likert scale. Interpretation of effect sizes will reflect Cohen’s suggested small, medium, and large effect sizes, where partial eta squared sizes are equal to 0.10, 0.25, and 0.40 respectively .
Age, school grade level, sex, socio-economic status and cultural background will be included as covariates in the analysis.