A treadmill (10) includes a frame on which are mounted transverse forward
and rearward roller assemblies (14, 16). An endless belt (18) is
trained about the forward and rearward roller assemblies. A deck (20) is
positioned between the upper run of the belt and the frame. The rearward portion
of the deck (20) is mounted to the frame by a pivot connection (24)
to allow pivoting of the deck about an axis transversely to the length of the deck.
Elongate springs (26) of adjustable stiffness are mounted either along the
sides of the frame to underlie the side margins of the deck, or transversely of
the deck, to support the deck in conjunction with the pivot connection (24)
and to absorb impact loads imparted on the deck by the user.