How long shall I practice Tai Chi/Qigong daily?

It depends on individual time and health condition. Practice till your spine with gentle perspiration.

To achieve gong build up or achieve rehabilitation result.

Ideally 3 times a day.

Morning: drink 2 cups of body temperature water, practice 1 hr before breakfast. Allow your body to wake up and get ready for daily activities.

Midday: before lunch. If you only have 1 hr lunch break, practice for 30 minutes.

In the evening: 1 hr after dinner or before bed. Tai Chi/Qigong and meditation will maintain your body and mind in a harmony balanced condition and sleep better (suggestion for insomnia patients).

Actually Tai Chi/Qigong is nature and body science, that is practicing abdominal breathing. You can practice at all time: in standing position, sitting position, lying position and walking.