Many consequences of illness and treatment can be positively influenced by physical training. There are now more than 700 randomized, controlled studies that prove the positive effects of exercise on cancer patients. Knowing what type of exercise, frequency, duration and intensity will have the best health effects is important for fitness trainers and physiotherapists working with people affected by cancer. Based on the current scientific data, the American College of Sports Medicine (ACSM) published new training recommendations for cancer patients at the end of 2019. These are summarized here.