Also, I find that if I get plenty of recuperative rest prior to a long trip, I am much more able to survive with less problems. SITC is absolutely right about travel exercises and moving about during journeys (when we travel by car, my husband stops for me about every 30 minutes so that I can get out, walk around, stretch, etc.). It might make your journey a bit longer, but at least you will arrive with less pain and/or problems.
Eat well before your trip and make sure that you wear sunscreen and protective clothing (UV rays can affect us even through the windows of trains and cars).
Hope your trip is enjoyable and that you arrive well enough to have fun!
Peace and Blessings
Look For The Good and Praise It!