(Not medical advice, just a personal reflection!) My Internet literature search on drug-free asthma methods has now led me to the Powerbreathe device, which may be considered as a means of intensifying nose breathing. It is obviously scientifically indicated for asthma, more so in fact than the many merely symptomatic and non-curative asthma drugs presently officially part of the identity of westerners.
With Powerbreathe and the many other similar gadgets inspiration is choked to a certain variable extent by breathing in through an adjustable aperture. The manufacturers speak of a training of the inspiratory muscles or “specific inspiratory muscle training” abbreviated as SIMT.
However what obviously must occur to an asthma-minded person is that we here have a remedial exercise for correcting mouth breathing, which is a well known cause of asthma, the details of the causative mechanism not being relevant here.
The manufacturers also show that not only nose breathing but also diaphragmatic breathing is trained.
The devices simply divert all input breath via the nose and this is much simpler than learning pranayama, which incidentally does not measure anything on a scale like said devices.
However, to put it in a nutshell, the purchase of a device is at least provisionally not required, because sucking air past/over a finger held between the lips but otherwise sticking to the devices’ instructions works just as well or better. In fact, the resistance to the inhale can be varied and the effect intensified toward the end so that diaphragmatic breathing is emphasized. RF