Raising the legs above the heart in an inverted position like this is supposed to calm the parasympathetic nervous system, relaxing and settling the system to aid relaxation and sleep. It is a restful position (if you find it comfortable and have strong enough legs and back to hold it comfortably for several minutes). Variations of this posture are suggested if you can't relax in this pose.
According the the sleep specialist , it is common to wake up 10-15 times a night anyway, a throw back to when we lived in caves and had to check that all was well with the world and we were not in danger. Women in late-stage pregnancy and new mums will typically wake up twice as much as this, more self-preservation and baby protection taking place it is assumed.
Top tips to improve your chances of getting a good night's sleep included:
- Incorporating a gentle, restful yoga sequence or meditation before bed
- Not keeping a clock in the room that is visible to you, and don't check the time if you do wake up, just try to go back to sleep
- Keep the room slightly cooler than the rest of the house
- Prepare for sleep well, write down and 'to-do's' before getting into bed so you don't worry about them in the night.
Hope this helps!