Williamson et al. 2022, Goal setting in sport, a meta-analysis

Systematic review and meta-analysis of goal setting in sport. Goal setting produces small but reliable performance and psychological benefits; goal type is the dominant moderator, with process goals producing large effects on performance (d ≈ 1.36), performance goals producing moderate effects (d ≈ 0.44), and outcome goals producing negligible effects (d ≈ 0.09). Effects are modest and variable, and much of the older evidence used non-athlete samples. Moderate.