Sport provides a significant role in the lives of athletes, however both positive and negative mental health effects may occur from sporting experiences, including burnout and/or well-being. A cross-sectional survey was conducted including 685 athletes (M age = 23.39, SD = 6.22, 71% = male), testing multiple, complementary, Self-Determination Theory (SDT) hypotheses linked to well-being and burnout. A multi-stage modelling approach encompassing confirmatory factor and path analysis was utilised, with results showing significant variance explained for well-being (R2=.30) and burnout (R2=.35). Several direct effects were found in line with SDT, including between; needs-support and needs satisfaction (β= .48), and needs-control and needs-frustration (β= .44); needs-satisfaction and motivational orientation (β= .25); needs-satisfaction and well-being (β= .37), and needs frustration and burnout (β= .25); motivational orientation and burnout (β= -.27), and motivational orientation and well-being (β= .18). Indirect effects were found for well-being and burnout via coach needs-support, needs satisfaction and motivational orientation in sequence (β=.24 and β=-.22, respectively); in addition to burnout via coach needs-control, needs frustration and motivational orientation in sequence (β=-.12). To conclude, coach-based, sporting mental health interventions that promote the utilisation of needs-supportive behaviours, whilst also highlighting the need to minimise needs-controlling behaviours, are recommended for the prevention of burnout and promotion of well-being in athletes
