Most people don’t realize how much contact their activewear has with their body — or how much that contact can actually matter. Your skin is your largest organ, and it absorbs far more than you might think, especially during intense workouts. That’s why non-toxic activewear isn’t just a feature of the EveryRep brand — it’s a foundation. It’s essential to your health.

When you’re moving, stretching, and sweating, your pores open up. That’s when synthetic fabrics like polyester and nylon — often treated with toxic chemicals — can start to leach harmful substances into your skin. The activewear industry is saturated with petroleum-based materials that contain BPA, PFAS, phthalates, and other endocrine-disrupting additives. These aren’t just bad for the environment — they’re dangerous to your body.

What’s Actually in Your Workout Clothes?

The chemicals found in conventional activewear aren’t trace contaminants — they’re built into the manufacturing process. Understanding what they are and how they affect your body is the first step toward making a safer choice.

BPA (Bisphenol A) is a synthetic compound used in the production of polyester and polycarbonate plastics. It acts as a synthetic estrogen in the body, binding to hormone receptors and disrupting normal endocrine function. Independent testing by the Center for Environmental Health found BPA in sports bras and athletic shirts from major brands at levels up to 40 times the safe exposure limit under California law. BPA exposure has been associated with reproductive harm, metabolic disruption, and immune system suppression.

PFAS (Per- and Polyfluoroalkyl Substances) are a class of synthetic chemicals widely used in activewear for their water-resistant and stain-repellent properties. Often marketed as “moisture-wicking” or “sweat-proof” finishes, these chemicals don’t break down in the environment or the human body — earning them the name “forever chemicals.” PFAS exposure has been linked to thyroid dysfunction, hormonal imbalance, immune suppression, fertility issues, and elevated cancer risk.

Phthalates are plasticizers commonly found in synthetic textiles and printed graphics on activewear. They are known endocrine disruptors that can interfere with testosterone production and reproductive development. Like BPA, phthalates can migrate from fabric to skin, particularly in warm, moist conditions — exactly the environment created during exercise.

Formaldehyde is used in some textile finishing processes to make fabrics wrinkle-resistant and colorfast. It’s classified as a known human carcinogen by the International Agency for Research on Cancer. While concentrations in clothing are typically low, prolonged skin contact — particularly during sweating — raises the potential for absorption.

Why Exercise Makes Exposure Worse

The risk from these chemicals isn’t theoretical — and it’s amplified by the very activity activewear is designed for. During exercise, several physiological changes increase your skin’s vulnerability to chemical absorption.

Your pores dilate as your body temperature rises, creating larger pathways for chemical transfer. Sweat acts as a solvent, dissolving chemical residues from fabric and carrying them into contact with skin. Blood flow to the skin increases dramatically during exercise to support cooling — meaning any chemicals that cross the dermal barrier enter systemic circulation more rapidly. And the areas of your body most in contact with activewear — chest, groin, underarms, waist — are among the most absorbent and hormonally sensitive regions.

This is why the fabric against your skin during training matters more than almost any other clothing decision you make. A cotton T-shirt worn casually poses far less absorption risk than compression leggings worn during a 60-minute HIIT session in a heated gym.

The Impact on Women’s Health

For women, the danger is especially serious when it comes to reproductive health, hormonal balance, and long-term fertility. BPA and PFAS are known to interfere with estrogen levels and have been linked to increased skin irritation, inflammation, and systemic hormone disruption.

Women’s activewear often involves the most skin-contact-intensive garments in the category — sports bras, compression leggings, and fitted tops — worn tightly against some of the body’s most hormonally sensitive tissue. The combination of compression, heat, sweat, and prolonged wear creates ideal conditions for transdermal chemical transfer.

Read our full technical report on how synthetic activewear affects women’s hormones, fertility, and reproductive health.

The Impact on Men’s Health

For men, the risks are equally significant — though far less discussed. Prolonged exposure to endocrine disruptors, particularly in high-heat, high-friction zones like compression shorts and underwear, can impact testosterone levels, sperm quality, and overall hormonal function.

Research by Dr. Ahmed Shafik demonstrated that men who wore polyester underwear experienced measurable decreases in sperm count and motility — effects that reversed when they switched to natural fibers. The mechanism involves electrostatic fields generated by synthetic fabrics against the skin, which interfere with normal reproductive function in the scrotal region.

The risks are real, and they’re closer than you think — right next to your skin.

What to Look for in Non-Toxic Activewear

Not all activewear marketed as “clean” or “sustainable” is genuinely non-toxic. Here’s what to look for when evaluating a brand’s claims:

Check the fabric composition. Avoid polyester, regular nylon (polyamide), and acrylic as primary fibers. Look for plant-based or cellulosic fibers like TENCEL™ Modal or TENCEL™ Lyocell, organic cotton, or merino wool. Pay attention to the percentage — a garment that’s 60% polyester and 40% cotton is still majority plastic.

Look for third-party certifications. OEKO-TEX® Standard 100 means the fabric has been independently tested for over 100 harmful substances. GOTS certification covers organic fiber content and processing. Be skeptical of vague claims like “eco-friendly” or “clean” without a named certification behind them.

Ask about the elastane. Nearly all activewear contains some elastane (spandex) for stretch. The question is whether it’s conventional petroleum-based elastane or a cleaner alternative like bio-based elastane or ROICA® V550 (biodegradable, Cradle-to-Cradle certified). The type matters for both skin safety and end-of-life biodegradability.

Verify BPA and PFAS testing. Some brands test at the fiber level only — which doesn’t account for chemicals introduced during dyeing, finishing, or assembly. The gold standard is finished-product testing that verifies the garment you actually wear is free from these compounds.

For a detailed breakdown of how common activewear fabrics compare on safety, performance, and sustainability, see our complete activewear fabric comparison. To understand why most moisture-wicking claims don’t hold up under scrutiny, read our technical analysis.

The EveryRep Approach

At EveryRep, we design performance wear that puts your body first. We use natural, plant-based fabrics like TENCEL™ Modal, known for their ultra-soft feel and breathable, moisture-wicking performance. Our materials are free from BPA, PFAS, and other toxic treatments, because we believe performance shouldn’t come at the cost of your health.

Every product in our line carries the BodySafe Guarantee: zero polyester, zero polyamide, and only biodegradable CiCLO® nylon where compression demands it — independently verified free from BPA, PFAS, phthalates, and other endocrine-disrupting compounds. From T-shirts and tank tops to sports bras, leggings, and underwear — every piece is built on the same commitment to fabric purity.

For our leggings and compression shorts where maximum compression is required, our BioLuxe® fabric — a premium nylon treated with CiCLO® biodegradable technology — delivers the performance of traditional synthetics without the toxic footprint.

It’s the difference between wrapping yourself in plastic… or wrapping yourself in nature.

Once you feel it, you’ll never go back. Shop our full non-toxic activewear collection.