Arriving at a destination marks a midpoint of a trip, not the beginning. By then, travelers have already trekked to the airport, navigated security and maybe caught a connecting flight. Much of that time is spent passively, either sitting in one vehicle or waiting to board the next. Often, the best options for physical activity and relaxation are to make like a mall walker or snag a coveted airport rocking chair. But that is changing.

In recent years, yoga and meditation rooms provided a low-impact boost to airport fitness and wellness amenities. Now, a crop of full-fledged gyms has sprouted in airports and onsite hotels worldwide, from Toronto and Chicago to Munich and Dubai.

For those who prioritize a workout over a charging station stakeout, it’s a welcome development. Customers pay a daily or hourly usage fee—typically between $10 and $40—for access to equipment, towels and showers. Munich Airport’s Kempinski Hotel Fit & Fly Spa even offers personal training services upon request. Many facilities also include spa-like amenities such as pools, saunas, massages, hot tubs and steam rooms to lure travelers who want to test out the trend without engaging in a full-on sweat session.

Airport gyms make most sense at mid-destination airports where extended layovers and long connecting flights are the norm. To appeal to fitness-minded world travelers who aren’t operating on local time, Dubai International Airport’s G-Force Health Club is open 24 hours.

Flight delays aren’t ideal, but they do present another opportunity to work out on the go. Travelers routed through Chicago’s O’Hare International Airport, which is frequently cited on most-delayed airports lists, may find themselves with extra time to visit the Hilton Athletic Club in Terminal 2.

By offering travelers the chance for a mid-journey workout, airport gyms help to counteract a common complaint—that making time for fitness on the go is too difficult. Leaving your exercise clothes in your checked luggage won’t let you off the hook, either. A number of airport fitness facilities offer workout gear for rent.

There are some complicating factors to consider when negotiating the combination of unscheduled time and exacting agenda that characterizes air travel. For example, anyone using a gym at an on-site airport hotel typically must leave the airport’s sterile area. That means you would have to clear security and/or customs again before boarding your next flight.

Be sure to keep track of time while working out, and stay alert for gate changes and status updates. The 10,000-square-foot GoodLife Fitness location at Toronto’s Pearson International Airport helps the cause by posting an Arrivals and Departures board on the wall near the warm-up area.