Embodiments of the disclosed polymer composition comprise a first unsaturated polymer or polymer precursor, and an effective amount of a peptizer. The peptizer typically comprises a heteroaryl or a heterocyclic compound, other than morpholine as disclosed in assignee's prior applications. Disclosed polymer compositions are useful for making sports equipment, such as at least one layer of a golf ball, often a core. Because the compositions are useful for making golf balls, materials commonly known for making such golf balls can be used in combination with the polymer composition. A method for forming a golf ball also is disclosed. The method comprises providing disclosed compositions and then forming at least one component of a golf using the composition.