Background/Objectives: Increased time and adherence to physical activity, as well as increased intensity of physical activity, is one of the determining factors in improving survival and avoiding disease recurrence in female breast cancer survivors. The study aims to determine the effect of a 12-session concurrent training program on increasing moderate/vigorous physical activity time in this population. Methods: A total of (N = 72) female breast cancer survivors were randomized into an intervention group and a control group to perform a 12-session concurrent training program. The GPAQ questionnaire measured the time and intensity of physical activity and work they performed before starting the program and three months after completion of the program. Results: A total of (N = 15) women in the intervention group and (N = 22) women in the control group completed the questionnaire before and three months after completing the program. A significant increase in moderate, vigorous, and combined physical activity (PA) was observed in the intervention group (IG) in comparison to the control group (CG) at three months following the intervention. While these results are promising, it is important to note that the observed improvements in PA adherence reflect associations rather than direct causal relationships. While these changes are statistically significant, they also reflect meaningful improvements in clinical outcomes. A notable finding was the significant decrease in sedentary time observed in the IG, which is likely to have contributed to the observed improvement in adherence. Conclusions: Concurrent training shows an increment in the time and intensity of daily physical activity performed by breast cancer survivors, which is a determining aspect of the survival and non-relapse of the disease in this population.
