You should prioritize brands that use recycled fibers, hemp, lyocell or organic cotton, carry certifications like GOTS or OEKO‑TEX, and publish transparent sourcing and labor practices. Look for durable, moisture‑wicking fabrics with a good fit for active movement. Top picks include Girlfriend Collective, Iron Roots, Colorful Standard and Thief&Bandit for ethical performance pieces. For running or yoga, favor recycled technical fabrics or breathable hemp blends. Keep going to find specific brand picks, fabrics and sale tips.