Run! That zombie behind you is gaining ground and ready to add you to his lunch menu.

If the creator of a new exercise app has her way, users will be doing just that: getting off the couch and doing a little running.

Elizabeth Lyons, a behavioral science researcher at the University of Texas Medical Branch at Galveston, recently developed the smartphone game Zombies, Run.

Lyons recently received a $140,000 grant from the American Heart Association to conduct a study on the effectiveness of the app, designed to be used by walkers or joggers. Each of its audio "missions" is accomplished by walking or running and monitored by a smartphone's GPS or accelerometer.

"It's this very compelling narrative that plays out in fake radio transmissions that come to you on your phone headset," Lyons stated in a press release. "If you're running outside in the dark, it really is like you are out scrounging for supplies after a zombie apocalypse, and this guy is radioing to you where you should go and telling you about things that are going on.

"The nice thing about the game is that it uses the power of narrative to create a vehicle for behavior change," she said.

As part of the study, which will involve 40 people, Lyons will compare the activity level of participants using the app with those not playing the game.

Online monitoring via the game's social networking system will give Lyons a real-time window into participants' activity levels, which will also be measured directly with armband accelerometers worn for a week at the beginning of the study and also at the six- and twelve-week marks.

Lyons is hoping that the end-of-the-world audio narrative will entice people who are usually sedentary to get out and move.

"Starting an exercise program involves lots of pain and lots of fatigue, especially for people who are sedentary and overweight," Lyons stated. "I'm interested in using games to distract people from that, and some of my other research has shown that narrative is really the most distracting thing."

The study's participants also will find a random 60-second "zombie chase" mode, where players have to walk faster or run to escape audible undead pursuers.

"A transmission comes through saying, zombies detected at however many meters, and you have to speed up by a certain percentage to outrun them," Lyons stated. "You can get really competitive when zombies are chasing you."