Effect of length of mindfulness practice - A randomized controlled experiment

Mindfulness-based programs vary in length of mindfulness practices included. It is expected that longer practice leads to greater psychological benefits. However, evidence for such dose-response effects is mixed. This study sought to clarify which length of mindfulness practice led to greater benefits using an experimental design. Participants were randomized to either four 20-minute mindfulness practices, four 5-minute mindfulness practices or audiobook control. All sessions were in-person over two-weeks and lasted the same total length. Participants refrained from formal mindfulness practice outside sessions. Both practices significantly improved trait mindfulness and distress compared to controls. Unexpectedly, short practice had a significantly greater effect on trait mindfulness (d=2.17;p<.001) and stress (d=-1.18;p<.01) than long practice. Even relatively small amounts of mindfulness practice can be beneficial. Short practices may be less challenging for novice practitioners when there is minimal teacher contact. Further research could examine these dose-response effects with experienced practitioners or prolonged teacher involvement.