If you have ever been to a yoga class or seen yogis practice online, you must know that they are beasts. Yogis are strong. Going from adho mukha vrksasna (handstand) into kudinyasana (arm balance) requires an immense amount of strength. Forget about these advance arm balances for a second, even to do a chaturanga you have to be fairly strong.
First off, any posture/ asana in yoga requires well developed abdpminal muscles (iliopsoas, rectus abdominus etc.) Your abs are the center of your body, hence the main location for stability and enabling balances of all kinds.
The most basic exercise to strengthen these muscles is the plank. If you have lower back problems, the plank pose puts little strain on the lumbar spine. Start out by holding a thirty second plank. Once you feel as if you are getting strong, keep adding thirty seconds until you get to five minutes. Once you reach five minutes call me, so I can congratulate you and stare at you enviously in person.
If you've tried plank and like me, if you get bored after twenty seconds let alone two minutes, then do a straight arm plank for thirty seconds and switch to a forearm plank for thirty seconds. Keep repeating this sequence until you've reached your time goal.
Another excellent abdominal exercise, is navasana/ boat pose. Hold navasana for two breaths, then lower half way down to a hollow body hold. After holding the hollow body pose contract your core and come back up to navasana. Repeat this ten times. Keep adding more sets as you get stronger.
For more strength building exercises, visit Hannah's blog!