The question of how long to train Tao meditation and energy arts is one of the most frequestly asked questions.
I advise all students, but especially beginners to qi gong, tai chi, bagua or meditation, to mind their two-thirds of effort in mind-body-qi, and save 45-minute to hour-long practices for many months (or even years) down the line, once they have a solid foundation in nei gong. Otherwise, you may injure yourself or build up too much internal resistance and stop practising.
Go with the flow and do whatever “clicks” for you yet try to build and sustain a regular practice. Try not to let the calculating mind prevent the inherent ebb and flow of your practice to be restricted or stifled. A naturally occurring phenomenon will drive your progression forward as the intuitive side of your mind-brain takes the helm and navigates the unchartered waters of your internal energy arts practice. Some days you might find that you naturally extend one aspect of your practice as you tune into a particular thread. It may or may not reduce the time you spend training overall.
All things considered, beginners are looking to initially practise 10-20 minutes a day, 3-5 days a week. Let this routine stabilise before increasing the length, frequency or intensity of your practice. Otherwise, the cunning mind of the intelligent person can find any excuse not to train as a rebound from the push. A gym sells 10 times the number of memberships that the facility can actual handle because too many people drop off after the initial thrust.
Don’t be one of those who give up. Start slow, increase your pace gently and play the long game to reap the real health benefits for which the internal arts have been well-known for millennia.