When I’m out riding my bike, I don’t pay too much attention to what I have on. But if I’m out for a run, or doing yoga, I’ve come to find that fabric is important. The right fabrics will keep you warm as you get started, but keep you cool once your heart rate goes up. Good fabrics will wick away perspiration. This makes for a much more comfortable workout. When you’re comfortable, you’re less likely to quit your workout early, or skip the next one.
The clothing I’ve purchased from both sources has lasted through hundreds of workouts, and still looks new. It’s lightweight, comfortable and unconstraining.