Enrollment proceeded to slowly

Overweight/obesity is associated with sub-fertility. The investigators will assess if regular exercise training prior to assisted fertilization will improve pregnancy rate in overweight/obese women referred to assisted fertilization. It is expected that training will be successful in increasing pregnancy rate

Obesity is associated with several diseases, as type 2 diabetes, cardiovascular disease and some types of cancer, this is of great concern for the public health. Also, of more immediate importance for these women; obesity is associated with increased risks of sub-fertility. The overall aim of the current project is to expand the knowledge about effective interventions to prevent the increasing prevalence of obesity-associated sub-fertility in population.

One cause of the increased referral rate for in-vitro fertilization is the growing prevalence of overweight and obesity. Currently, about 700 couples are annually referred for in-vitro fertilization at St.Olav's Hospital. In this interdisciplinary trial, involving physiotherapists, exercise physiologists, gynecologists, and basic researchers, the effects of regular high intensity exercise training on fertility in sub-fertile overweight and obese women will be investigated.

Inclusion Criteria:

• body mass index (weight in kg/height in cm squared) >25
• accepted for assisted fertilization treatment at St.Olav's hospital

Exclusion Criteria:

• low responders, defined as AMH <2 pmol/L or < 5 oocytes in prior in vitro fertilisation (IVF)/Intracytoplasmic sperm injection (ICSI) cycles or antral follicle count (AFC) < 5
• current or previous Metformin use (a wash-out period of > four weeks)