- Start on ground in plank position, balancing on forearms and toes, hands clasped, so body forms a straight line from head to heels.
- Tip tailbone up, arching back slightly, then tuck pelvis under, reversing arch to flatten back and pull abs tight; hold contraction for 5 counts.
- Do 8 to 10 reps.
Trainer's Tip: This is a subtle movement: Hips lift very slightly, as shown, not into a high inverted V as in downward dog.
Originally published in FITNESS magazine, July/August 2010.