We've discussed health and travel before, but if you're going to travel healthy, there are some things we can add.... and there are some things that bear repeating!
We've said that you should be healthy when you leave on your trip. A last minute cold aside, you don't want to be climbing on a plane if you have the flu or some serious illness. That seems obvious, but people do it all the time. Not only will you be miserable, but you might be infecting others on the plane with you.
Most people can leave on a trip without consulting their doctor, but for some itineraries, it's wise to get a check-up. If you're planning a trip to an exotic location, meet with your regular doctor or your travel medicine doctor.
Find out if you need any vaccinations or medications for your trip. They can probably give you a prescription for a broad spectrum antibiotic and give you instructions on how to take it in case you get diarrhea and need it.
If you have some health issues, like a heart condition or something that limits you, discuss with your doctor the proper care you should take for those conditions to keep your travel healthy.
Make sure your teeth are in good shape too.
Be sensible about what you eat and drink on your travels. Eat what you like, but if things look unhygienic, you might want to take a pass. If food looks like it's been sitting out for the flies for a few hours, you wouldn't want to eat it anyway.
Try to eat nutritiously. If you have a dietary restriction, try to learn how to say it in the local language (or get it written down). And let the restaurants know... ask if they can help you if you need to avoid something for health reasons.
If you have serious food allergies, like allergies to shellfish or peanuts, you should carry an EpiPen or its equivalent. Of course you'll try to avoid the culprit, but in a foreign country, you may not get your point across, so it's better to be prepared. A precaution like this not only keeps your travel healthy... it could keep you alive!
Drink bottled water in places where the water isn't safe. It is usually pretty easy to tell where that is. Drink tea or coffee made with boiled water, or drink bottled or canned soft drinks, beer or wine.
You have to watch your own hygiene as well as the water and the food. Make sure your hands are clean. Wash them before eating... or use those hand sanitizers that are available now. They come in small packets that you can take in your carry on luggage.
Get in shape for your trip so you'll feel good about all that walking and all those stairs. Try to get plenty of exercise when you're on your trip. And get plenty of sleep.
Sure you want to run around and not miss anything, but if you're going to travel healthy, you need to rest... that way you will be able to keep going, and you will see it all.