For passengers stuck between flights on airport layovers, several U.S. airports now offer beneficial alternatives to browsing junk food outlets or occupying bar stools.
The latest airport to join the fitness craze is Phoenix Sky Harbor, which opened PHX Fitness Trail in May, a two-mile interior fitness trail with seven free bottle-filling water stations.
Travelers who have time on their hands between flights can embark on the two-mile walking circuit (inside the TSA checkpoints) that circles Terminal 4, the airport's busiest.
A handy map, points of interest, mileage and photos are included in a free brochure that passengers can pick up at Terminal 4 information counters.
There's no place to stash carry-on bags while doing the circuit, due to security concerns, so fitness aficionados need to take the roller bag or backpack along the route, as well.
Passengers who glance up and out during their walks will see Camelback Mountain, the Phoenix-area landmark; South Mountain Park/Preserve, the largest municipal park in the U.S.; Piestewa Peak, named after a member of the Hopi Indian tribe, and the PHX Sky Train bridge, which passes over an active taxiway.
Dallas/Fort Worth Airport unveiled its DFW LiveWell Walking Path inside Terminal D two years ago to give passengers an option to exercise while on the go.
The path measures seven-tenths of a mile and is marked with signage as well as by in-floor mosaics that represent progress points along the way from gates D6 to D40.
The walking path also features two optional step courses in the form of 55-foot-high staircases at Terminal D's two Skylink people-mover stations.
There's also a yoga studio at gate D40 as another optional activity.
The path is sponsored by LiveWell, the airport's employee wellness program, which launched in 2008.
The path was "a giant step toward our goal of making DFW the nation's healthiest airport," according to Jeff Fegan, who was CEO at the time.
Currently, DFW ranks as the fifth-best airport for healthy eating, with 79% of the on-site restaurants offering at least one plant-based, fiber-packed entree, according to the Physicians Committee for Responsible Medicine's 2013 Airport Food Review.
Boston's Logan Airport features walking paths as well as four health stations in Terminals A, B and C where passengers can check blood pressure, height and weight and test for Body Mass Index.
The stations are marked by 8-foot-tall signs.
It's all part of a Strides for Health initiative launched by Boston-based Steward Health Care System at Logan in December.
"Experts agree that as little as 30 minutes of brisk walking several times a week can positively impact health," said Juliet Nimako, a primary care physician at Steward Health Care.
Passengers pick up a free Strides for Health map that details the walking paths and the length between concourses.
Passengers at Indianapolis Regional Airport can walk off some calories and tally their mileage by following markers in the airport corridors.
The idea is modeled after walking paths in parks, the difference being that the obstacles inside terminals are people wheeling large carry-on bags instead of joggers and bikers.