Holding a shallow version of a pose for a long time will not be as useful as proper engagement of the muscles for a shorter period of time.
Each Posture is Different
Each posture demands a different level of effort. By design, some postures require immense amounts of physical strength and others require no strength at all. Fingerstand (pictured above) will never be the same difficulty level of something like Half Tortoise. This means Fingerstand will be held for less time.
The goals of the postures are all different. Instead of thinking about how many seconds we should hold the pose, we need to think about how much effort is being exerted. This will give us a sense of how long it’s reasonable to hold.
We should not try to mediate our effort over a certain period of time. For example, Half Moon Sidebend is often taught by holding the pose for a long time. This means that most people adjust their posture by holding a shallow version. This is not very useful. The postures are muscular engagements. We should try to use our muscles to the extent that we have the strength. Doing a very small amount for a long period of time is not as beneficial as using the muscle properly for a shorter amount of time.
The second reason that teaching to time is not useful is because each person is different. For a newer practitioner, a short hold is very difficult. For an experienced practitioner a longer hold of the same posture may be easy.
There is no “one time fits all” method. The amount of time to hold a pose depends on what the pose is and the comfort and experience level of the practitioners.
