Muscle Mass full brother to Gold Leg Winner SHEER ENERGY (f, 2, 1:58.1s -'19 ($57,208), half brother to MANOFMANYMISSIONS 2, 1:53.2f, 3, 1:52.1 -'11 ($1,213,603), and half sister to the dam of HELLO TOMORROW 2, 1:56.3 -'19 ($52,919)