Jason Mah, of Catonsville, has found a new way to both get his mountain biking training in and his lawn mowed at the same time: its a bicycle-powered lawnmower constructed by Mah and a friend, and it gets the job done. (Jon Sham/Baltimore Sun video)

If you're driving on Seminole Avenue in Catonsville, you may spot a homeowner taking a different approach to mowing his lawn.

Jason Mah, 40, an avid cyclist, has created a contraption that allows him to cut his lawn, while riding his bicycle.

"I'd have to mow my lawn or pay someone to mow my lawn — it's a definitive given," Mah said. "And it dawned on me one night — why am I paying someone to mow my own lawn when I could be biking and mowing it at the same time? I'm going to be killing many birds with one stone."

Although not as precise as a typical lawn mower, the contraption leaves few blades behind. But it does attract attention.

The custom-built mower consists of a push reel mower, without the handle. A custom-made arm attaches the push reel mower to Mah's silver mountain bicycle. The arm also prevents the mower from hitting the bike's rear tire and allows the bicycle to make turns. A 10-pound sandbag attached to the top of the mower adds enough weight to the mower to prevent it from toppling over.

"Steering is not your typical biking — you have to take a longer, wider route," Mah said. "It's not like a zero turn riding motor where you can turn on a dime. You have to plan ahead and plot your route."

It's not unique. A Google search shows there are hundreds of similar machines around the country.

"It really mows well. If you let it get too long, it doesn't do as good of a job," said John Jacob, who helped build the lawn mower. "But it forces you to exercise harder."

It takes about 15 minutes to mow the front yard, which is flat. Cutting the grass in the backyard takes about 30 minutes, due to the incline with the house being built on a hill, Mah said.

"It's a pretty strenuous workout," said Mah, a product manager for a mobile advertising startup company.

His wife, Erica, said her husband is always trying to find ways to save money and get exercise.

The pedal-powered lawn mower was the perfect solution, she said.

The contraption not only offers a way to exercise, but is also beneficial to the environment.

Each year, Americans burn 800 million gallons of gas cutting their lawns, according to the Environmental Protection Agency.

One gas-powered motor releases 88 pounds of greenhouse gas carbon dioxide and 34 pounds of other pollutants into the air, the EPA says.

"I think he was inspired to do this because it covers so many of the things that he cares about," Erica said. "A lot of the things that he believes in come together with this."

"It's a lot of fun, and it's great when you have an idea that you can materialize," Mah said.

Mah said he enjoyment of alternatve workouts inspired the idea to build the contraption.

Three years ago, he began doing Brazilian jiu-jitsu, a martial art he describes as "human chess."

He has also recently taken up slacklining, a way of practicing balance that involves using a nylon strap tethered between two anchor points.