摘要:Study aim: To assess the effects of an eight-week pedometer-based walking intervention, using different strategies of goalsetting, on self-efficacy, physical activity enjoyment, and body image. Material and methods: The study included data from 82 girls, aged 16 to 18 years. The participants took part in the intervention using goal setting with the do your best strategy (do your best group, n = 26) or specific step goals predetermined by the researcher (predetermined goals group, n = 56). The group of participants from the predetermined goals group was divided into a group of those achieving the goals (n = 28) and a group where goals were not achieved (n = 28). Self-efficacy, body image, and physical activity enjoyment were assessed before and after the intervention. Results: The results of ANOVA with repeated measures between the measurement times and groups showed a significant effect of body image (F = 3.60, p = 0.03, η² = 0.08) and physical activity enjoyment (F = 3.10, p = 0.05, η² = 0.07). Participants who achieved goals in step counts predetermined by the researcher had a more positive body image and a higher level of physical activity enjoyment after the intervention. Conclusion: An eight-week pedometer-based walking program implemented in a school setting may improve body image and physical activity enjoyment in adolescent girls only if the set goals (the number of steps) are specific and fully achieved by participants. Using pedometers in conjunction with a goal setting program seems to be an effective motivational way to improve physical activity in female students.