An air mattress or bed is disclosed. The air mattress has a first panel, a spaced second panel, and at least one side panel extending between the first panel and the second panel, each panel being joined to the other along their common peripheral edges to define a single air chamber therebetween. At least one mattress coil is disposed within the air chamber and is affixed to and extends therein from the first panel to the second panel. The air mattress further comprises at least one side support beam extending in the lengthwise direction of the at least one side panel. The side support beam has a first edge affixed to the at least one side panel and a spaced second edge affixed to at least one of the first panel and the second panel.