movement of the device 10 by the user when the sliding attachment 50 is used and less resistance when the attachment 50 is not used referring to fig8 a 8 c a method of using the device described above is illustrated in this method the device 10 is positioned on a sheet polyethylene or polypropylene mat shown generally at numeral 90 this mat 90 has a narrow base 92 with outwardly extending oblique sides 94 and 96 and a widened front side 98 a kneepad 100 is positioned on the mat 90 adjacent the narrow base side 92 a user 102 positions his her forearms 104 and 106 respectively on the forearm receiving pads 36 and 38 the user 102 is thereby able to grip hand grips 32 and 34 on the front arc 30 with his her hands 108 and 110 respectively the user 39 s knees 112 and 114 remain in a stationary position on the kneepad 100 in the first step in the method of using the device 10 the user moves forward generally in the direction of the centerline of his her body as at arrow 116 in fig8 a at the completion of this step 102 the user will have extended his her body from the arched back position shown in fig8 a to the extended nearly prone position shown in fig8 b once having reached the extended nearly prone position shown in fig8 b the user then slides the device rearwardly in the direction of arrow 118 along the centerline of his her body until the arched back.