I travel constantly but don't take the supplements like you.
I run when I can, which is usually fun in a new place, plus make use of the hotel gym.
So there's aerobic + weight = a pretty good workout. I was a swimmer so I swim laps if there's a long pool.
Plus, I make a conscious effort to put a much walking into the day as I can, always take the stairs not the elevator whenever possible, stuff like that. That really helps.
If you don't like to run, they say you still get a pretty good workout from a long walk, so you might consider that.
The worst is airplane confinement trapped in air that's years old, filled with everyones' sneezes, food smells, etc. All you can do is stretch often.