The Hollywood couple often enjoys a break from the spotlight by getting back to nature on trips to the great outdoors.
But during one vacation in Colorado, Holmes failed to pay attention when they were planning their activities - and she ended up on a hair-raising mountain climb.
She tells Britain's Hello! magazine, "One time we planned to do a lot of hiking in Colorado and we had a meeting before the first day. I was on my BlackBerry and I wasn't paying attention. All I knew was that it was going to be a long hike.
"So the next morning we go and all of a sudden our guys pull out some harnesses. And I was like, 'What do you mean? Are we going to go up the side of a mountain, really climbing?' So my husband went in front of me because a harness does not look good on anybody. From then on I have paid more attention in meetings."