According to the Straits Times, Nike is introducing more sports apparel based on tricked out new fabric technologies:

A Nike Fall 2005 Innovation Session for the Press was recently held by Nike Malaysia to show its latest technology. Seated at tables prepared with swatches of three types of Nike Sphere React materials — Nike Sphere React Dry, Nike Sphere React Cool and Nike Sphere React Pro — we were invited to dab them with water and observe how each fabric responded. Each is built around proprietary materials engineered for a specific purpose.

Nike Sphere Dry reduces cling to help keep the athlete dry. Nike Sphere React Cool promotes increased airflow to help keep the athlete cool. Nike Sphere React Pro releases moisture vapour while repelling water, to help protect the athlete from the outside environment.

Each technology incorporates bio-mimicry, drawing on principles in nature to help solve a human problem — keeping cool, warm and protected through the various stages of a workout.

The apparel companies are trying to develop gear that will fit goldilocks consumers looking for something that's not too hot, too cold, but is just right.