The intervention group follows a one-hour in-person intervention focused on acceptance of stress. Each participant follows this intervention individually.

The control group follows a 20-minute online psychoeducation at home. Each participant follows this intervention individually.

The intervention consist of explanations and exercises about acceptance of stress. The intervention starts with a welcome, after which participants do jumping jacks and then breath through a straw to induce an uncomfortable experience. Next, a Chinese finger trap is used to show the automatic, but often not useful, reaction to avoid stress. Participants then watch a short video that introduces the concept of acceptance, and they do a short, guided meditation. Afterwards, they do the straw exercise again, but this time with instruction to examine and allow uncomfortable experiences. The session ends with a recap and the introduction of the home exercise. Participants install an app that reminds them every hour to do a three-second meditation in which they pay attention to their breathing and body in an accepting way.

Psychological well-being was measured with the General Health Questionnaire-12 (GHQ-12, Goldberg & Williams, 1988), which is a unidimensional measure of mental health with good psychometric properties (Romppel et al., 2013). Higher scores on the GHQ-12 indicate more psychological distress and lower well-being.

The six-item version of the Spielberger State-Trait Anxiety Inventory (STAI; Marteau & Bekker, 1992) is a brief, valid, and reliable questionnaire to assess participants' state anxiety.