THURSDAY, Nov. 13, 2025 (HealthDay News) -- In patients receiving treatment for metastatic breast cancer, supervised aerobic and resistance exercise improves lean mass, muscle strength, and physical performance, according to a study presented at the Advanced Breast Cancer Eighth International Consensus Conference, held from Nov. 6 to 8 in Lisbon, Portugal.Anne May, Ph.D., from the University Medical Center Utrecht in the Netherlands, and colleagues conducted the PREFERABLE-EFFECT study to assess a nine-month supervised aerobic and resistance exercise program in 354 patients with metastatic breast cancer.The researchers found that exercise significantly improves physical performance, including balance, and muscle strength at three and six months, compared with usual care (control group). Whole-body lean mass increased in those participating in the exercise program and decreased in the control group, with the effects significant after three months. Muscle mass in arms and legs increased significantly in the exercise group (average of 0.6 kg at three months and 0.48 kg at six months compared with the control group). The skeletal muscle mass index also increased by an average of 0.22 kg/m2 and 0.18 kg/m2, respectively, versus the control group. There was no difference in whole-body fat mass between groups. "The results from our study are important since lean body mass is linked to better treatment tolerance, prognosis and overall health, and increased muscle strength correlates with improved quality of life and lower mortality risk," May said in a statement. "This supports the call for exercise, and specifically supervised exercise with a resistance exercise component, to be integrated as a standard component of cancer care for patients with metastatic breast cancer."Press ReleaseMore Information.Sign up for our weekly HealthDay newsletter