Chances are, your favorite exercise attire is synthetic, made from petroleum-based fibers like nylon, spandex and polyester. Materials that don’t exactly scream “climate friendly.”

Natural fibers have issues, too: Growing cotton can use huge amounts of water and pesticides, the sheep that give us wool emit methane, and processing bamboo can produce a lot of pollution. Altogether, the apparel and footwear industries account for more than 8 percent of global greenhouse gas emissions.

So if you want to keep your body fit while also keeping the planet healthy, what should you do?

Consider recycled fibers

There’s a lot of plastic polluting our lands and waters. Some companies have capitalized on that, melting down plastic waste and extruding it into yarn.

Karen Leonas, a professor of textile sciences at North Carolina State University, said those materials could be a good choice for workout clothes.

“Any time you can find something that contains recycled fibers, that’s definitely a plus,” she said. “Whether you’re looking at climate, water, solid waste or even social sustainability issues.”

Lewis Perkins, president of the nonprofit Apparel Impact Institute, also said he liked recycled fibers. But he cautioned that they’re a “transitional solution,” as he believes the ultimate goal should be reducing the prevalence of single-use plastic in the first place.