The experimental arm will receive the online strengths use intervention program over a period of 6 weeks, through an LMS software solution.

The online strengths use intervention program, will be based on Miglianico et al.'s (2020) general framework, following the theorized five stages: (1) preparation and commitment, (2) identification, (3) integration, (4) action, and (5) evaluation.

As to increase participant engagement and motivation, gamification components will be embedded in several of these stages.

The entire intervention will be delivered online via an LMS software solution.

Work engagement will be measured with the Utrecht Work Engagement Scale (UWES-9). It has 9 items that form three dimensions, each with 3 items: vigor (e.g., "At my work, I feel bursting with energy"), dedication (e.g., "I am enthusiastic about my job"), and absorption (e.g., "I am immersed in my work"). This measure uses a 7-point agreement scale (0 = never, 6 = always).

Psychological capital will be measured with the 12-item Psychological Capital Questionnaire. It has four subscales: hope ("At the moment, I feel quite fulfilled at work."), self-efficacy ("I feel confident presenting information to a group of colleagues."), resilience ("Usually, at work, I easily get over the stressful aspects."), and optimism ("I am optimistic about what will happen to me in the future regarding my job."). All 12-item are reported on a 6-point Likert scale (1 = strongly disagree, 6 = strongly agree).

Strengths use will be measured with a set of six items, rated on a 0 (almost never) to 6 (almost always) Likert scale. A sample item is "I seek opportunities to do my work in a manner that best suits my strong points".

Burnout will be assessed with the 12-item Burnout Assessment Tool (BAT). This questionnaire has four subscales: exhaustion (3 items; "At work, I feel mentally exhausted."), emotional impairment (3 items; "At work, I feel unable to control my emotions."), cognitive impairment (3 items; "At work, I have trouble staying focused.") and mental distance (3 items; "I struggle to find any enthusiasm for my work."). All items will be scored on a 5-point scale ranging from 1 (never) to 5 (always).

Satisfaction with the intervention will be measured using 22 items. We will use 6 items aiming at the program's content retrieved from a questionnaire used for measuring the alliance between trainers and trainees. The minimum score is 6 and the highest is 42. A higher score means a better outcome (increased satisfaction with the intervention). Also, we will use 16 items retrieved from a scale previously used for measuring the satisfaction with an online intervention. Nine of the items are measured on a Likert scale. The minimum score is 7 and the maximum is 42. A higher score means greater satisfaction. 7 items are open-ended questions.