Being an artist is typically a pretty stationary profession. Maybe you’ll walk a few steps to the easel, then a few more to the rack of paint. 

But that’s not the case for artist Lenny Maughan, who racks up as many as 30 miles to make one sketch. For Maughn, the streets of San Francisco are his canvas; his feet the brush. And the resulting image actually appears on Strava, a fitness app that records runners’ times and charts their routes. Call him the Jogging Giotto.

Last month, Maughan’s work went viral when a friend shared on Reddit the artist’s latest effort, an exacting line portrait of Frida Kahlo, whose likeness Strava mapped from Maughan’s run. The run spanned 28.93 miles, 3,500 feet of elevation change, and took more than six hours.

Courtesy of Lenny Maughan and Strava.

Maughan, who has lived in San Francisco for more than two decades, has been making his running pictures for more than three years now. The planning sometimes takes as long as the execution. First, he prints out several paper maps of San Francisco and then draws his way through the little streets like a maze on the back of a cereal box. Sometimes he’ll go through several copies before he finds a route that works.

“I have to plan them very precisely in advance,” Maughan recently told Runner’s World. “I just dream up shapes of things—random, unexpected, timeless, widely recognizable, often kitschy or quirky things to ‘draw’ using the city streets as my canvas. Either I’ll look for patterns in a street map or I’ll try to make a shape fit within the lines of the streets, and then I sketch it out on a paper map with a highlighter. It goes through several iterations before I get it just right.”

Courtesy of Lenny Maughan and Strava.

Maughan’s first image was the Vulcan hand signal from Star Trek, inspired by the death of Spock actor Leonard Nimoy. “I just printed out a paper map and sketched a hand shape along Market Street and the other fingers, thumb and wrist came pretty easily,” he told the Guardian. After that came a maze-like television. (The first TV was created in San Francisco in 1927.) “The larger you go, the more fine-tuned you can make the shape.”

Since then, his work has grown increasingly complex. There’s a taco, a rose, a heart, a pair of hands holding chopsticks. There’s a martini glass, a guitar, and the Starship Enterprise. There’s the busty woman that appears on the backs of truck mudflaps. Once, Maughan even “drew” a self-portrait of himself running. In total, his portfolio is now some 50 pictures deep. 

See more of Maughan’s pictures below.

Courtesy of Lenny Maughan and Strava.

Courtesy of Lenny Maughan and Strava.

Courtesy of Lenny Maughan and Strava.

Courtesy of Lenny Maughan and Strava.

Courtesy of Lenny Maughan and Strava.

Courtesy of Lenny Maughan and Strava.