The best three TRX exercises for abs are ideal when travelling, in your home, in a park, anywhere for that. No gym needed. Keep it slow, controlled and squeeze.
You can pickup a TRX here or a new favourite, those little yellow dumb bells you can see in the bottom corner, Drybells. The portable kettle you can fill with sand. I’m addicted to it. You can find my exercise videos with that here and travel workout plans here.