QUIT LOOKING AT THE INTERNET!!!!!!! GO DIG A HOLE IF YOU'RE BORED! Honestly, looking online for ways to stay fit is about as counter intuitive as a doughnuts only weightloss plan. I have found myself the most fit when I keep busy, generally working on a farm or building site. Wanna have muscle definition, and lose some fat? Just go do something.
Sorry, I will edit this and clarify a little.
Exercise is such a joke to me. it is such a fucking waste of time. If you actively pursue something that takes physical work, you WILL exercise your body, as well as accomplish something, maybe learn something...
Go dig up a parking lot and make a guerrilla garden. Go recycle 1000 pallets and build a shanty. There are countless things you can do that will help you pass the time, and do a lot more for you than exercise. it doesn't take equipment, just a minimal amount of creativity, some passion, and some drive. If you are lacking those qualities, you need a lot more help than exercise.
You are advocating lifting bags of dirt, slabs of concrete... People get paid for this! Go do Day labor 3 times a week, get fit, and make some cash in the process...
That's kind of like saying don't go to the library to read books about car maintenance so you can fix your car.
Every body is different. Also, we're talking about fitness while traveling, which often has periods of just sitting around. So just saying "go do something" isn't very helpful in reality.