You can enjoy these two exercises anywhere, at any time.

Further reading
Two: Daoist
The key to qigong is combining breath with movement. Even when still, the in- and out-breath can be guided through acupuncture points, nourishing the organs and then stored in the centre or dantian.

Microcosmic orbital breathing
The two channels through which the qi circulates are:

• Ren or Conception channel starts in the perineum and runs up the front of the body to the dip between the chin and bottom lip
• Du or Governor channel starts between the coccyx and anus and runs up the spine, over the head to down to the inside of the mouth where the gum and lip meet

Tip of tongue to roof of the mouth (‘Making the Magpie Bridge’) connects the two channels, enabling this microcosmic orbit or circulation of internal energy using the breath. This classic Daoist qigong meditation also known as ’circulation of light’ involves deep, breathing exercises, mediation and concentration that has a fantastic effect on the whole body. Daoists believe that the Microcosmic Orbit meditation fills the reservoirs of the Governing and Conception channels with energy, which is distributed to all the major energy meridians, thereby energising the internal organs.

Symbolism
Microcosmic Orbit draws abundant energy up from the sacrum into the brain and, in doing so, enhances the cerebral circulation of blood and stimulates secretions of vital neurochemicals. It is also the first stage for cultivating the ‘Golden Elixir’ of immortality, a process that begins in the lower abdomen and culminates in the mid-brain. This is probably the best of all Daoist methods for cultivating health and longevity, while also ‘opening the three passes’ to higher spiritual awareness.

I will be teaching the microcosmic orbital breathing in my Friday
Qigong class also online.

Three: Current research
Milennia after Buddha and the Dao taught these techniques, in his new book Breath, James Nestor argues that humans have lost the ability to breathe correctly, with damaging consequences that reach beyond snoring, asthma and allergies. Drawing on ancient wisdom and the latest scientific studies he argues that the most effective way of breathing to enhance the lung capacity and oxygen uptake and reduce is to breathe in and out through the nose for 6 seconds for the in-breath and 6 seconds for the out-breath.

In an experiment at Stamford University, the negative effects of mouth breathing for 10 days were both physical (increased blood pressure, snoring, sleep apnea) and mental (focus, memory issues and fatigue). When breathing through a labyrinth of structures in the nose, air is heated and moistened, so that pathogens and pollutants are extracted. This is a first line of defence.

Interestingly he talks about the yogic practice of alternate breathing:

So in a way, we have gone full cycle using western research to uncover the ‘lost knowledge’ or ‘scientifically prove’ what the Daoists and Yogis have known all along.