I'm currently exploring a longer Recaka kumbhaka (holding the breath out after the exhalation) in Krishnamacharya's one minute Uttihita Padangustasa, the description in Yoga Makaranda (Mysore 1934) is fascinating.
We have Krishnamacharya mention alignment,
"...While standing this way, make sure that the head, neck, back, hips, arms and legs are aligned properly..."
the gaze,
"...and gaze at the tip of the nose".
clear instruction for the breath,
"..Inhalation and exhalation of the breath must be slow and of equal duration". (for the first photo)
and kumbhaka (retaining the breath in or out) instruction, here the kumbhaka is after the exhalation in the second photograph.
"...While standing this way, make sure that the head, neck, back, hips, arms and legs are aligned properly..."
the gaze,
"...and gaze at the tip of the nose".
clear instruction for the breath,
"..Inhalation and exhalation of the breath must be slow and of equal duration". (for the first photo)
and kumbhaka (retaining the breath in or out) instruction, here the kumbhaka is after the exhalation in the second photograph.
"...Recaka kumbhaka must be done in this sthiti. That is, expel the breath completely from the body, maintain this position and then without allowing any breath into the body, bend the upper body. Now carefully pull in the stomach as much as one’s strength allows and hold it in. Stay in this sthiti for at least one minute..."
Krishnamacharya also mentions his interest in blood circulation,
"...Because of this asana, our body’s important areas — the arms, legs, knees, hips, bones of the back, the buttocks, stomach, neck — these will be cleaned. Not only this, it will facilitate proper clean blood circulation in the nerves."
an interesting reference to Nadi as nerve bundles,
"Those who practise this can, even on the first day, recognize the changes in the location and movements of the nadi (that is, what are the regions where our nerve bundles are not in the correct state or proper position)."
he even mentions props...
"Those who cannot do the asana properly on the first day may stand using the support of the wall, place the raised leg on top of a table and then follow the instructions described above. But if done this way, the benefits are much fewer. After practising this way following the krama for 5 or 6 days, learn to do this asana without any aids."
and includes a practice 'tip',
"...Initially, when you first practise this without any support, you might fall down. In that case, after slowly exhaling the breath out, firmly hold the breath. This will prevent a fall. "
Note too that while Krishnamacharya takes the big toe in the first sthiti he holds either side of the foot in the second sthiti, (less strain on the hamstring and sciatic nerve than pulling back on the toe).
"...Initially, when you first practise this without any support, you might fall down. In that case, after slowly exhaling the breath out, firmly hold the breath. This will prevent a fall. "
Note too that while Krishnamacharya takes the big toe in the first sthiti he holds either side of the foot in the second sthiti, (less strain on the hamstring and sciatic nerve than pulling back on the toe).
***
This posture can be challenging, slow breathing to the abdomen, firmed by the posture' can help as well as perhaps employing some of the other relaxation techniques Simon Borg-Olivier mentions in his new Introduction to breath control (pranayama) course (see THIS post) I.E. The Twelve Bridges Between the Conscious and the Unconscious Mind to Assist in Relaxation and Breath- control. Staying relaxed in the posture helpsin making the kumbhaka following the exhalation more comfortable.
Utthitahasta Padangushtasana
After staying in this sthiti for some time, take either the face or the nose towards the knee of the raised leg and place it there. Recaka kumbhaka must be done in this sthiti. That is, expel the breath completely from the body, maintain this position and then without allowing any breath into the body, bend the upper body. Now carefully pull in the stomach as much as one’s strength allows and hold it in. Stay in this sthiti for at least one minute. At this time, the knee must be kept straight without bending. Remember this when you practise. In the beginning, it might not be possible to do this properly. But if one keeps practising following the given rules for 10 to 15 days, it will become possible to do it properly.
Because of this asana, our body’s important areas — the arms, legs, knees, hips, bones of the back, the buttocks, stomach, neck — these will be cleaned. Not only this, it will facilitate proper clean blood circulation in the nerves.
Those who practise this can, even on the first day, recognize the changes in the location and movements of the nadi (that is, what are the regions where our nerve bundles are not in the correct state or proper position).
Those who cannot do the asana properly on the first day may stand using the support of the wall, place the raised leg on top of a table and then follow the instructions described above. But if done this way, the benefits are much fewer. After practising this way following the krama for 5 or 6 days, learn to do this asana without any aids. Initially, when you first practise this without any support, you might fall down. In that case, after slowly exhaling the breath out, firmly hold the breath. This will prevent a fall.