The keen ones message me for something the morning after they land. It is a lovely instinct and I usually try to talk them out of it.
What travel actually does
Several hours of sitting shortens the hip flexors and lets the spine settle into a rounded position, and the discs are less hydrated than usual. Cabin air dehydrates you further, and altitude and immobility make everything a bit stiffer than it looked at home.
Then there is the time difference, which is doing something to your coordination and your judgement that you cannot feel and can definitely measure.
The specific risk
It is not the stretching. It is the confidence.
You arrive fit, motivated, on holiday, with a week of good intentions, into a class you would ordinarily manage. The shape is available. The control is off by a small amount, and small amounts are how people spend day three of a trip with an ice pack.
What to do on day one
Walk. Genuinely. The town is small and everything is close, and thirty minutes on your feet does more for a travelled body than an hour of anything ambitious.
If you want a class, take a slow one. Restorative if I have it on. Something where the hardest decision is which side to lie on.
Day two onwards
Then go properly. By the second or third day you are hydrated, you have slept in the right time zone once, and the class you wanted is the class you can actually use.
The thing people get wrong about holiday practice
They front-load it. Four classes in the first three days, nothing after.
Spread it. Two classes a week apart teaches you more than four in a row, and you will still be walking comfortably at the end of the trip, which is the part your last two days depend on.