Pump for article of footwear or apparel

An article of footwear comprising:

• a pump comprising:
• a conduit defining an inner volume and formed from a flexible material, the conduit movable between an expanded state and a relaxed state and extending from a first end disposed at a medial side of the article of footwear to a second end disposed at a lateral side of the article of footwear;
• a coil disposed within the conduit and including an outer diameter that is approximately equal to an inner diameter of the conduit, the coil substantially maintaining its outer diameter when the conduit is moved between the relaxed state and the expanded state;
• and
• a manifold in fluid communication with the inner volume and operable to permit fluid to enter the inner volume in a first mode and expel fluid from the inner volume in a second mode.