Hug a Twinky/Gag a Giant - Yes, it's an odd name. This is for lower back, hamstrings, and glutes. On a vaulting horse lie down so that your legs are dangling and the edge of the vault is at your lower abs. Lift your heels as high as you can, so that you are esentially standing on your chest, lower slowly. Some other object can be substituted for the vault. (The gag a giant term comes from the new vault).