Objectives: Junior doctors are frequently exposed to occupational and traumatic stress, sometimes with tragic consequences. Mindfulness-based and fitness interventions are increasingly used to mitigate this, but have not been compared.We conducted a randomised, controlled pilot trial to assess the feasibility, acceptability and effectiveness of these interventions in junior doctors., Methods: We randomised participants (n=21) to weekly 1-hour sessions of personalised, trauma-informed yoga (n=10), with a 4-hour workshop, and eHealth homework; or group-format fitness (n=8) in an existing wellness programme, MDOK. Burnout, traumatic stress and suicidality were measured at baseline and 8 weeks., Results: Both interventions reduced burnout, and yoga increased compassion satisfaction within group on the Professional Quality of Life scale, without difference between groups on this measure.Personalised yoga significantly reduced depersonalisation (z=-1.99, p=0.05) compared with group fitness on the Maslach Burnout Inventory (MBI-HSS (MP)) and showed greater flexibility changes. Both interventions increased MBI Personal Accomplishment, with no changes in other self-report psychological or physiological metrics, including breath-counting.Participants doing one-to-one yoga rated it more highly overall (p=0.02) than group fitness, and reported it comparatively more beneficial for mental (p=0.01) and physical health (p=0.05). Face-to-face weekly sessions were 100% attended in yoga, but only 45% in fitness., Conclusion: In this pilot trial, both yoga and fitness improved burnout, but trauma-informed yoga reduced depersonalisation in junior doctors more than group-format fitness. One-to-one yoga was better adhered than fitness, but was more resource intensive. Junior doctors need larger-scale comparative research of the effectiveness and implementation of individual, organisational and systemic mental health interventions., Trial Registration Number: ANZCTR 12618001467224., Competing Interests: Competing interests: BR is the Chief Medical Wellness Officer, WellMD Centre, Sydney Local Health District. JT worked separately to the trial as a group yoga and meditation instructor on the MDOK programme., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)