Don’t let irritating t-shirts hold you back in your daily activities. Introducing the Muscle Tee. Crafted from Tencel, an ultra-lightweight and exceptionally soft fabric, the Muscle Tee wraps your skin in lasting comfort. Its straight cut and side slits ensure optimal freedom of movement. Now you don’t have to choose between comfort and sustainability - the Muscle Tee uses ten times less water than cotton, significantly reducing its environmental impact.

100% Europe

100% recyclable

Our raw materials are meticulously sourced in <strong>Europe</strong>, and each product is crafted in Portugal. Every Circle product is designed to blend high performance with a commitment to the planet, using sustainable (recycled and natural) and traceable materials. With 100% of production in Europe, we’re setting a new standard for a positive impact in the running industry. Our Fairly Made traceability score is 5/5. Circle proudly achieved B Corp certification in March 2024, with a score of 96.1.