Mijwel S, et al. - Given that patients with breast cancer undergoing chemotherapy showed positive effects of a 16-week supervised exercise on their physiological and health-related outcomes in the OptiTrain trial, researchers undertook this inquiry to determine how rates of chemotherapy completion and hospitalization, as well as blood cell levels during chemotherapy are influenced by exercise. In a randomized manner, women (n = 240) scheduled for chemotherapy were assigned to 16 weeks of resistance and high-intensity interval training (RT-HIIT), moderate-intensity aerobic and high-intensity interval training (AT-HIIT), or to usual care. Chemotherapy completion, hospitalization, hemoglobin, lymphocyte, thrombocyte, and neutrophil concentrations during chemotherapy were assessed as outcomes. Findings revealed that neither RT-HIIT nor AT-HIIT beneficially influenced chemotherapy completion rates. However, hospitalization rates were effectively attenuated with combined resistance training and high-intensity interval training, and a positive influence of both exercise groups on thrombocytopenia was also evident.