The ornamental design for an exercising apparatus, as shown and described.
1. Exercising apparatus
1.1 : Perspective
1.2 : Perspective
1.3 : Front view
1.4 : Back view
1.5 : Top view
1.6 : Left view
1.7 : Right view
This exercising apparatus fills the inside with water and can be used for walking exercise, running exercise in water and can also be used as a spa bath; the bottom view is omitted.