Before you go
Fitting in a strength and conditioning class first thing in the morning and then heading out for a run in the evening. Of course this did help with the flight being so late, but even if your flight is earlier you can get something in. This has to be one of the benefits with living in Melbourne and it only taking 30-40minutes to get to the airport, as we soon discovered after arriving in the UK, getting stuck in traffic and travelling back home adds another 3 1/2 hours to an already long journey.
On the flight and at the airport
Once we arrived at Singapore airport, we had a 3 hour stop over period. After an 8 hour flight and then with a 12 hour flight, we just tried to do as much walking/standing as possible, with the exception of sitting down whilst we were using the foot/calve machine (these are just amazing, and just helped getting the blood flowing again). I also took the myofascial release ball, just to release the muscle tension in my back. This is a perfect accessory to have in your travel bag, its light, small and easy to carry.
Getting Over the Jet Lag
Dave bought his TRX system, these are all light weight and apart from the roller don't actually take up that much room. Of course the roller you can fill up with all your gym gear.