The study aimed to investigate the physical activity of eighth graders (n=20) in one southern Finnish school. The study evaluated the effects of guided recess exercises on activity, coping, and well-being at school. Data collection for the study was carried out over two weeks in January 2023, measuring physical activity with motion meters and well-being using a questionnaire. The study was carried out with a quantitative research approach.

The SPSS Statistic 26 program was used to analyze the research data. The data was described by using mean values. The analysis of variance was used to compare the mean values between the first and second time of measurements. The Wilcoxon test was used to measure subjects' experiences with recess exercises. The association between increasing recess exercise time and school satisfaction was measured with correlations.

According to the results, moderate and vigorous physical activity increased statistically significantly in both genders with the help of guided interval exercise. Standing still during breaks also decreased significantly, on average approximately 19 minutes. Gender was not found to have a statistically significant difference in increasing physical activity or decreasing sedentary time.

According to the questionnaire based on the experiences of students after intervention week, the subjects responded that they felt they could handle the school day better and that they felt less tired after the intervention week. In addition, loneliness was felt less, and during recess, there was a greater request for guided exercise. The change between a normal week to intervention week was statistically significant.

The study results were in the same direction as previous studies, both in terms of physical activity and well-being at school. However, it should be noted that there have not been many measurements of physical activity during breaks specifically with movement meters and, on the other hand, the sample size of this study was relatively small, hence far-reaching generalizations cannot be made.