Recycled material blends in cycling pants use repurposed polyester or nylon—often from plastic bottles or fishing nets—instead of newly manufactured fabrics. The good news is that today's recycled blends perform virtually identically to their virgin counterparts in terms of stretch, moisture wicking, and durability, so you're not giving anything up on the bike.
The main trade-off is usually price: recycled fabrics tend to cost a bit more due to the sourcing and processing involved. You're paying a small premium for the reduced environmental footprint rather than for extra performance. That said, many premium cycling brands now offer recycled options, so you're not limited to entry-level choices.
If sustainability matters to you, recycled material cycling pants are a solid pick. Just check that the spandex or elastane content still hits that 15–20% sweet spot for proper stretch and shape retention—recycled or not, that's what keeps your pants from sagging mid-ride.