Chemotherapy for cancer, due to its gonadotoxicity, can lead to impaired female fertility, resulting in the occurrence of transient or prolonged chemo-induced amenorrhea (CIA). According to recent data from the National Cancer Institute, 11.9% of women under the age of 40 diagnosed with cancer have been offered a fertility evaluation within five years of diagnosis. Predicting the risk and especially the duration of the CIA remains difficult. Known factors predicting a rapid return of menstruation are a young age at diagnosis, a low gonadotoxic treatment (absence of alkylating agents) and a high pre-chemotherapy blood level of AMH reflecting a large pool of growing follicles. A body mass index (BMI) ≥ 25 kg / m² could also be a positive predictor, but this remains debated. The objective of this project is to assess the impact of metabolism and energy reserves, physical activity and the chronotype on the recovery of ovarian function in patients with breast cancer who have developed CIA