You'll blast abs, obliques, lower back muscles, and glutes by combining sprinter situps and gator rolls in this at-home, no-equipment core finishing move from Ebenezer Samuel, C.S.C.S.

The best part: You can do this core series anywhere.

• Start with your back on the ground, lower back glued to the floor, arms and legs slightly off the ground. Contract your abs and lift legs and shoulder blades off the ground. You're now in a hollow hold.
• Roll over to the left onto your belly and then your back quickly; do this without letting arms or legs touch the ground. You should land in a hollow hold.
• Go right into sprinter situps: Maintain a hollow hold and elevate your torso while tucking your right knee to your chest. Then return to a hollow hold and repeat the move on the other side. That's 2 reps.
• Gator roll to the other side; now do 4 sprinter situps.
• Repeat the pattern until you've completed the round of 10 sprinter situps.
• Rest 1 minute; do 3 sets.