Where Philadelphians exercise, according to GPS app Strava

The news this week that the locations of Fitbit-wearing U.S. military personnel in Afghanistan could be seen using GPS data shown on the Strava Labs website, has set off security alarms from those concerned the publicly available maps could potentially give away sensitive information.

In November, Strava, an app that tracks physical activity using GPS, updated their Global Heat Map to include one billion activities, marked by three trillion latitude and longitude points that cover 17 billion miles or about 5 percent of the planet, according to their website.

In our region, the GPS data is a window into where greater Philadelphia residents run, walk, bike and in some cases swim. The data is collected through the use of smart phones, Fitbits or Garmin watches. It also provides a glimpse into areas where there is no fitness data.

Strava Global Heatmap
Camera icon Strava Global Heatmap
Swimmers using GPS devices are recorded as they swim laps at John B. Kelly pool in Fairmount Park, while larger swaths of data chart rowers on the Schuylkill River, right.

Not unsurprisingly when looking at the water sports map, the Schuylkill River near Boathouse Row, a go-to spot for rowers, shines like a bright path. But look inland toward Fairmount Park and you will see that lap swimmers with GPS devices at John B. Kelly pool have also left their digital mark. Switch to the bike or run maps and the paths along Kelly Drive and Martin Luther King Drive light up.

In Bucks County, the wooded area just west of Neshaminy High School is aglow with students’ cycling data points.

“We have a mountain biking program,” explained Principal Rob McGee.

The school has about eight lifetime sports options for physical education classes including rock climbing, badminton, pickleball and walking. The environmental area by the school is loaded with trails that are used by students and some community members. The students get safety training beforehand, then check out the school’s fat tire bikes and ride, he said.

“It is pretty busy in the spring and fall,” McGee said.

Camera icon Strava Global Heatmap
Students using mountain bikes during physical education classes at Neshaminy High School light up the area outside their Bucks County school.

At Nockamixon State Park outside of Quakertown, there is a distinctive triangle located in the middle of the lake near the Tohickon Boat Launch.

“That is exactly our swim course,” said Dale Winterhoff, director of the popular Steelman Open Water Swim and Triathlon. The data is probably collected from the Garmin watches used by the swimmers to monitor their number of strokes as well as their heart rates and locations, he said.

Camera icon Strava Global Heatmap
Data charting swimmers with Garmin sports watches and Fitbits in Lake Nockamixon show the triangle course of the Steelman Open Water Swim race.

The Steelman swim course is set up in the lake by the Haycock Volunteer Fire Company and Rescue using GPS. The course varies slightly from year to year in location, not distance, Winterhoof said.

He noted that when you look at the data for bicycling and running or walking in the same area, you can see the popular routes the athletes use to train for the races. The lake also is a popular destination for kayakers and paddleboarders which is also shown on the Strava map, he said.

“It looks like they are really lighting up,” Winterhoff said.

There are plenty of predictable areas in Philadelphia that light up with data points like Forbidden Drive in the Wissahickon Valley Park. But for the city to take full advantage of the information provided by Strava to make any changes to current policy, it would have to purchase the actual data from the company and not just look at the map, said Jennifer Crandall, spokeswoman for the city’s Parks and Recreation Department.

“We don’t have that kind of budget,” said Crandall. There are also city departments that can help with mapping using GPS information to get an idea of what is happening in certain areas, she said.

The Strava data is also a window into where GPS fitness information is absent.

While the track at Sun Valley High School in Aston glows with GPS data, nearby Chester High School and the surrounding community gives a much less active recreational footprint.

Camera icon Strava Global Heat Map
Streets in Camden show little activity in contrast to the popular jogging paths along the Cooper River.
Camera icon Strava Global Heatmap
The track at Temple University glows with data from those who walk or jog on the track.

The areas near the waterfront, Cooper Hospital and east along the Cooper River trails, show plenty of activity but not so much in the city of Camden.

Parts of Philadelphia near Kingsessing, West Philadelphia and the area surrounding Temple University – where the track glows like a neon light – are mostly bereft of the GPS tracking data lines.

“Not everybody has a smart phone or a fitbit,” said Crandall.