Cancer patients are now more often long-term survivors and their needs for returning to social and productive activities have become a primary focus of intervention. The purpose of the present study was to propose an objective evaluation test for predicting endurance capacity in breast cancer patients after surgery, in order to optimize return to work or previous daily activities, and for monitoring changes during rehabilitation. Twenty female patients (mean age: 44 +/- 5), who underwent radical breast surgery 2 months before being referred to our Unit, participated in the study. In addition to the measures of the circumferences in the arm-forearm and manual muscle strength test, we performed the following functional evaluations: 0-100 Constant scale for shoulder function; instrumental evaluation of daily/occupational upper limb activities (Lido WorkSET). We monitored the mechanical parameters, the perception of effort, pain or discomfort, and the range of movement while performing a 3-minute steady daily/occupational task chosen by the subject. Patients were asked to perform the 3-minute test at three different intensities ("moderate", "somewhat hard", "hard") until the perception of fatigue, pain or discomfort was rated > 3 on the 10 point Borg's scale. The 'power-duration' product (Watt x min) defined by the three tests (see Fig. 1) represented the individual tolerable work load, since subjective indicators of pain/discomfort remained within tolerable limits during the exertion. On this basis, patients were encouraged to return to levels of daily physical activities compatible with the individual tolerable work load. The second evaluation, although no statistical analysis was performed, confirmed that the "guided" daily activity in a 2-month period increased patients' capacities and "trust" in their physical capacity.