Harvard University researchers have some bad news for Pokemon Go enthusiasts: The time you spend hunting digital monsters doesn’t qualify as a workout.

After analyzing the movements of players, the researchers calculated that Pokemon Go encouraged people to take an average of 955 extra steps per day in the first week after downloading the game. Assuming that each step covered 31.5 inches and that players walked at a pace of 2.5 miles per hour, the game prompted people to walk for 11 extra minutes each day.

That’s not much. The World Health Organization recommends that adults get at least 150 minutes of aerobic physical activity each week. If you spread that equally throughout the week, you’ll need to get 21.4 minutes of exercise each day — twice as much as Pokemon Go provides.

And that was just for the first week. In subsequent weeks, players spent less time walking around catching monsters; by the sixth week, they were back to their pre-Pokemon Go habits.

But researchers allowed for the possibility that the game does more for players than their step counts would indicate.

“Other potential benefits might exist, such as increased social connectedness and improved mood,” the researchers wrote. On the other hand, they added, “Pokemon Go might also entail risks, such as injuries and road traffic incidents.”

Pokemon Go has been downloaded more than 500 million times since it hit smartphones in July.