It's sitting down for long periods in any situation, even workaholics who never move from their desks have had them.
No.1 is keep hydrated, sip water no alcohol and wear flight socks, they really do work. I used to get very swelly ankles but with the socks it really reduces it.
Choose an aisle seat so it's easier to get up and stretch your legs and have a walk to the loo. I love the window seat but now choose aisle as I get a bit stiff and need to get up more, plus being stuck when the person on the end is asleep makes me feel trapped now.
Eat light food, most airlines now have a range of dietary options plus it also means you get fed first!!
Depending on your height check if there is a foot rest. If you're a shorty if the airline doesn't have them then take an inflatable foot rest because then the seat won't cut into the back of your leg or have your legs dangling which adds to the risk.
Take an aspirin before a flight to help keep the blood thin. Also take a jumper, most flights run cool and although they give you a blanket it helps to take an extra layer as being cold contributes to clots.
Do some stretches whilst waiting in the loo queue.
You'll also have a stop over to NZ so make the most of having a good walk around the transiting airport.
Win the lotto and fly first class....
![Grin ;D](https://www.menopausematters.co.uk/forum/Smileys/extended/grin.gif)
Hope this helps from a seasoned traveller! Enjoy NZ it's a beautiful country!