What Does Four-Way Stretch Mean in Activewear Fabric Specifications?

Four-way stretch means an activewear fabric extends in both its lengthwise and crosswise directions.

It does not mean equal stretch in both directions, and it does not specify how strongly the fabric resists extension or how well it recovers. A useful purchase specification records extension and recovery in each direction under agreed conditions. Check those properties in the proposed fabric and evaluate the finished garment at its intended fit.