What does Boxing Day have to do with boxing?
hypertrophy hy·per·tro·phy (hī-pûr'trə-fē)
A nontumorous enlargement of an organ or a tissue as a result of an increase in the size rather than the number of constituent cells. v. hy·per·tro·phied, hy·per·tro·phy·ing, hy·per·tro·phies
To grow or cause to grow abnormally large.