Stair climbing apparatus and method

1. A stair stepping apparatus comprising:

a plurality of stairs mounted on a frame and hingedly interconnected to each other in succession to form a treadmill or endless belt, the treadmill being rotatably mounted on the frame for rotation around a path of travel,

wherein each stair comprises:

a step having a generally planar upper step surface having a front to rear length extending from a front edge to a rear edge, and,

a riser having a top to bottom vertical length extending from the rear edge of the upper step surface to a bottom edge of the riser,

the riser comprising an upper riser and a lower riser hingedly joined to each other between the rear edge of the step surface and bottom edge of the riser.

2. The stair stepping apparatus of claim 1 wherein the upper riser is rigidly interconnected to the rear foot support at the rear edge of the upper step surface such that the upper riser is disposed normally below the upper step surface, the lower riser being rigidly interconnected to a front foot support of a successive step at the front edge of the upper step surface.

3. The stair stepping apparatus of claim 1 wherein the step comprises a front foot support and a rear foot support hingedly joined to each other between the front and rear edges of the upper step surface.

4. The apparatus of claim 3 wherein the treadmill is mounted for rotation such that the stairs travel in a backwardly downwardly directed path of travel on rotation of the treadmill, the front and rear foot supports of successively interconnected stairs providing a step surface on which a user can step with a user's foot during at least some portion of the backwardly downwardly directed path of travel of the stairs.

5. The apparatus of claim 1 wherein the treadmill is interconnected to a resistance device that exerts a selected degree of resistance to rotation of the treadmill, the treadmill being rotatably driven against the resistance by force of the user's weight or by the user's exertion of downwardly directed force on a step surface of one or more of the stairs.

6. The apparatus of claim 1 wherein the path of travel of the treadmill has a longitudinal axis disposed at an angle of between about 30 and about 36 degrees relative to horizontal.

7. A method of performing an exercise by a user using the apparatus of claim 1 , the method comprising the user's stepping on a stair of the apparatus of claim 1 while the treadmill of the apparatus rotates in a backward and downward direction.