A turbine bucket may include a platform, an airfoil extending from the platform at an intersection thereof, and a cooling circuit extending within the platform and the airfoil. The cooling circuit may include a root turn with an asymmetric shape to reduce stress concentrations therein. The asymmetric shape of the root turn may be asymmetrical along a path between a pressure side of the airfoil and a suction side of the airfoil. The asymmetric shape of the root turn may be asymmetrical within a plane defined by a radial direction and a circumferential direction.