Do changes in autonomous motivation mediate the effect of the EuroFIT programme on physical activity?

Gender-sensitized approaches to health behaviour change in sports settings have generated positive health outcomes and health behaviours, but theoretical constructs integrated in these interventions have not been tested as mediators of change. The European Fans in Training (EuroFIT) programme used motivational strategies from Self-Determination Theory (SDT) to promote health behaviour change in overweight male soccer fans (n = 1113; mean age of 45.9 [SD = 9.0] years old and mean BMI of 33.2 kg/m² [SD = 4.6]) across 15 professional soccer club settings in the UK, Portugal, Norway and the Netherlands. A causal mediation analysis of the randomised controlled trial (RCT) of EuroFIT examining indirect effects of autonomous motivation, controlled motivation or amotivation on objectively measured and self-reported PA at 12-months follow-up for men who participated in the trial was undertaken. We also tested whether the men’s identification towards their soccer club moderated the mediating effects of these forms of motivation on PA. We found that autonomous motivation had a small indirect effect on objectively measured (b =.164, 95% CI: [.033,.303], p =.010) and self-reported PA (b =.285, 95% CI: [.089,.488], p = <.001) in men at 12-months follow-up, however, these effects were non-significant when controlling for increases in PA at post-programme and were not robust to residual mediator-outcome confounding. We found some evidence that men’s identification towards their club moderated the mediating effect of autonomous motivation on objective PA, but not self-reported PA. This represents preliminary evidence that men’s club identification can influence the relation between a key construct in SDT and sustained PA.