In the axial position, the methyl group experiences steric crowding (steric strain) because of the presence of axial hydrogen atoms on the same side of the ring (known as the 1,3-diaxial interactions). There are two such interactions, with each pairwise methyl/hydrogen combination contributing approximately 7.61 kJ/mol of strain energy.
In an axial configuration, the methyl group encounters spatial interference due to the presence of axial hydrogen atoms on the same side of the ring (1,3-diaxial interactions), leading to a total of two such combinations that contribute approximately 7.61 kJ/mol of strain energy.