Here are some strength training calisthenics that require no equipment just your own body weight.
The first exercise is a standing crunch. Put your hands by your ears bring, your elbows up tall. Breathe out as you crunch down. Come up all the way and over exaggerate the motion pulling your chest tall, chin up.
Next, stand tall one arm up and the other arm down to your side. Stretch your arm up to the sky, reach and bend at the waist while concentrating on the ribs stretching.
The last exercise is for the back. Reach forward like your grabbing the horses rains and pull all the way back nice and slow squeezing your shoulder blades. Breathe out as you pull your arms toward your body.
Always try and workout as often as possible even when you're on the road.