The goal of this multi-center randomized controlled trial is to investigate the effect of pre-operative exercise therapy and education for patients awaiting knee replacement surgery on subjective knee function, patient satisfaction and enablement compared to standard care. The main questions it aims to answer are: * Does pre-operative exercise therapy and education lead to better subjective knee function compared to standard care one year after surgery? * Does pre-operative exercise therapy and education lead to a higher level of patient satisfaction compared to standard care one year after surgery? * Does pre-operative exercise therapy and education lead to better patient enablement compared to standard care six weeks after surgery? * Does pre-operative exercise therapy and education lead to better objective knee function compared to standard care six weeks after surgery? Participants will be randomized stratified by age (≤ 67 years, \> 67 years) to either pre-operative supervised individualized exercise therapy combined with education two sessions/week (intervention group) or to standard care (control group). The intervention will be continuously ongoing for at least eight weeks from the point of decision for surgery until as close to the surgery as possible.