Inclusion Criteria:  Living in Copenhagen, Denmark or surrounding area - making it possible to engage in strength training 3 times a week at Bispebjerg Hospital, Copenhagen, Denmark. ≥ 18 years old  Exclusion Criteria:  Illness or physical handicap making it impossible to participate in the training intervention Pregnancy Not Danish or English speaking Anemia Already performing regular structured physical training Strict vegan or vegetarian diet Illness or ongoing treatment that hinders study examinations