“They're both avid travelers.”
You had a dinner party at your house last week. Now you're talking with your roommate about one of the couples who came, who she doesn't know well. They travel a lot, so you say this.
They're both avid travelers.
When someone likes to do a certain activity a lot, you can describe them as "an avid ___".
You complete the phrase with a noun like "traveler": it's a label that describes the category of people who like to do that activity. Here are some other examples:
an avid reader
an avid fan
an avid gardener
an avid runner
The word "avid" sounds positive and intellectual.