This yoga posture is a gift - but you must be able to do it easily and comfortably, in order to safely benefit from it's substantial benefits. For those, who cannot easily achieve this posture, please desist! For those to whom the latter applies, you will need to work towards achieving this posture, over time. Ideally, with the supervision of a yoga instructor. In the interim, you can raise your legs by leaning them against a wall, with your arms by your sides, palms up. Then, continue with the other important beneficial aspects of this exercise.
Breathe in deeply through the nose
Hold the breath for 10 seconds
Breathe out drawing in the tummy/abdominal muscles tight
Now as you take your next in-breath, allow your tummy muscles to completely relax. Continue for 5-10 mins, or longer if desired.
If you can hold your breath for longer than 10 seconds, by all means do so. Remember to be sensible, and not to overdo it.
This is a very helpful posture to employ in your life on a regular basis. I would recommend doing this exercise whenever you feel tired, stressed, needing contemplative respite or in need of a pick-me-up. The more frequently, the better.
The benefits of this exercise are bountiful, including the following important aspects: