Fight to keep your legs flexed and together with toes pointed during the hollow positions and keep the small of your back in contact with the floor the entire time.
Do this work in order
a) 20 GHD Situps
-rest 90 sec.
b) 6 min. Rolling hollow/arch :45 sec on/:15 sec off
(15 sec hollow, seal roll to 15 sec arch, 15 sec hollow, 15 sec rest)
-rest 90 sec.
c) 20 GHD situps