Mark Mertens

A4S Sportswear creates high-performance apparel for the outdoor athlete (runners, trail runners, hikers) who pursue their sports year-round. Our initial focus is on dedicated runners, especially marathoners, who train and race in all four seasons. Unlike mass-market brands that prioritize fashion over function, our innovative business model enables A4S to craft premium products using the most sophisticated fabrics and designs. We design for thermoregulation, which is the most critical factor in optimizing performance to meet athletic goals.