Scientists have developed a web-based app that encourages users to get enough exercise, by allowing them to go on virtual walking tours of locations such as the Grand Canyon in the US.
The game, designed by researchers from University of Iowa in the US, can be played with by anyone with a smartphone and a Fitbit.
"We essentially found that people who received the game right out of the gates increased their steps by about 2,200 per day, which is close to walking one mile," Lucas Carr, an associate professor at University of Iowa in the US.
The game, called MapTrek, syncs data from accelerometers - in this case Fitbits. Using Google Maps, MapTrek then moves a virtual avatar along a map in proportion to the number of steps the participant takes.
Participants of the study were grouped together and competed against one another in weekly walking challenges each week.
"You can see what place you're in and see where you're at on this map. Every week, the race changes to a different place in the world -- the Appalachian Trail, the Grand Canyon," Carr said.
Using Google's street view function, users can click and see where they're at in real time, effectively turning the game into a virtual walk or race through different locations.
MapTrek also sends users text messages each day to remind them to wear their Fitbit and also to provide encouragement. Users also could take part in daily challenges to earn bonus steps.
"We tried to make it as enjoyable as possible. We want people to wear their Fitbit and we want them to participate in these games," Carr said.
For the study, 146 participants - sedentary office workers, ages 21-65 who reported sitting at least 75 percent of their workday - were divided into two groups.
Both were given Fitbits, but only one group used their Fitbit along with the MapTrek game. Their activity levels were monitored with the Fitbit's activity monitor.
During the 10-week study, the researchers found that the Fitbit and MapTrek group walked 2,092 more steps per day and completed 11 more active minutes per day compared with the Fitbit-only group.
Active minutes are defined as those in which the participant took more than 100 steps.
"If a person can maintain a daily 2,000-step increase, that could result in a clinically significant improvement in their overall health. It's associated with about a 10 percent relative reduction in long-term incidence of cardiovascular disease," Carr said.