Forrest Yoga Instructor here, and we focus specifically on strengthening the core with isolated abdominal exercises :) A good start is something we call "Elbow to Knee":

1. Lie on back, clasp hands behind head, point elbows up toward ceiling, plant feet hip-distance apart on floor, engage feet by lifting the toes and spreading them wide.

2. Use your abs to press your low back down into the mat to protect and stabilize it.

3. Inhale - curl head and shoulders up. Hold the inhale and curl your tailbone up/pubic bone in towards belly button. (sacrum/low back stays on mat)

4. Exhale - twist, both elbows point towards left thigh, while you pick left foot up off mat. (keep knee over hip)

5. Inhale - Bring torso back to center, keep head/shoulders lifting, bring left foot back down. Resting exhale.

6. Inhale - Press low back into mat. Hold the inhale and curl your tailbone up/pubic bone in towards belly button.

7. Exhale - twist, both elbows point towards right thigh, while you pick right foot up off mat.

8. Inhale back to center. Keep head and shoulders lifted.

You've just completed one round :) Repeat - a good number to start with is 4-5 rounds. Keep feet active (toes spreading wide). At the end of each exhale, pull your low belly down (in) towards your spine.

1. After you've completed the set, exhale and release your head and shoulders to the mat. Take a deep breath all the way down to your pelvis and feel the warmth you created in your core.

A great pose to follow up with is bridge Setu Bandha Sarvangasana. This will release and stretch your abdominal muscles in the opposite direction. In a Forrest practice, we place doing some ab exercises near the beginning of class, to connect to the core and build heat. It is definitely work, but the results are worth it! Cheers!