It’s to improve your back, not your backhand.

Over the years (and miles), I’ve trimmed my list of “must haves” in my carry-on. One thing that always makes the cut on long flights: a tennis ball. And that’s even if I don’t have a court booked at my destination.

No, it’s not to have something to bounce against the  airplane cabin wall. (Don’t do that. Really.) It’s to help with inflight stretching.

Long-haul flights can have many adverse health effects—swollen feet, bloating and gas, constipation, skin breakouts. Longer flights can also result in blood clots and tight muscles, which is how the tennis ball comes in handy. Note: I buy the cheaper youth ones ($3.50/3 balls).

Roll the ball across your shoulders, the small of your back, the backs of your calves, the soles of your feet, and any other areas that feel sore or tense. Add pressure until you feel pain of the good kind, then relax into it. The massage action increases in your circulation, which helps release and soften knots and tight areas.

After you’ve done that, take a stroll up and down the aisle. And hydrate regularly with water! Avoiding alcohol and wearing compression socks can also help with circulation.

If you don’t have a tennis ball, you can hand-massage your legs, stroking your muscles from the ankles upwards to help get the blood flowing back to your heart. (The tennis ball makes it easier, though, both in terms of reaching the bottoms of your feet and not disturbing your seatmate.)

Note: It’s not a bad thing to do in between Zoom calls at home.

Twist’s Take: Fly with a tennis ball and improve your back instead of your backhand.