Most people have no idea what their gym shorts are made of. They should. The answer starts with crude oil and ends against your skin.
Where polyester actually comes from
Polyester is not a fabric in the traditional sense. It's a plastic. Specifically it's PET, polyethylene terephthalate, the exact same polymer used to make plastic water bottles, packaging, and fuel containers. It starts as crude oil, gets refined into petrochemicals, and is then processed into the fiber that gets spun and woven into the shorts sitting in your drawer right now.
Crude oil → petrochemicals → PET plastic → polyester fiber → your gym shorts.
That's the chain. Most brands don't put that on the label.
What "performance fabric" actually means
The athletic wear industry has built an entire vocabulary to make petroleum sound sophisticated. Moisture-wicking. Dri-FIT. ClimaCool. AEROREADY. Engineered fabric. Four-way stretch. Ventilation zones.
Strip the language back and the question is simple, what is this material, and what is it doing against your skin for hours at a time? Research increasingly links prolonged contact with synthetic textiles to skin irritation, disrupted moisture regulation, and the leaching of hormone-disrupting compounds including phthalates and BPA-adjacent chemicals found in plastic-based fabrics. Your skin absorbs more than most people realize.
The recycled bottle myth
Some brands have found a clever workaround. They take PET plastic bottles, shred them, re-spin the material into fiber, and sell the result as sustainable performance fabric. The messaging is clean. The reality isn't.
Recycled PET is still PET. It sheds microplastics just as readily as virgin polyester, hundreds of thousands of microscopic plastic fibers per wash cycle, passing straight through most wastewater filtration systems and into waterways, oceans, and the food chain. Studies have detected synthetic microfibers in human blood, lung tissue, and the placenta.
Recycling the bottle doesn't change what the fiber does once it's woven into fabric and worn against your body. They repackaged the problem and called it sustainability.
Cotton is not complicated
Cotton breathes. It wicks moisture naturally without trapping heat. It doesn't shed microplastics. It's a crop, renewable, biodegradable, worn directly against skin for thousands of years before petroleum became a fabric option. It gets softer with every wash. Polyester pills, sheds, and degrades.
Spring is the wrong time for polyester
Synthetic fabric traps heat. As temperatures climb that problem gets worse. If there's a moment to rethink what you're wearing to the gym, it's now.
The Sol Short is 100% natural cotton. 300gsm. OEKO-TEX certified. Cotton USA certified. No blends, no synthetics. Two deep pockets, metal aglets, 4.5" inseam.
Single — $54 Duo — $92 (save $16) Trio — $133 (save $29)