I claim the ornamental design of a cylindrical oxygen therapy exercise bag, as shown and described.
FIG. 1 is a perspective view of a cylindrical oxygen therapy exercise bag;
FIG. 2 is a front view of the cylindrical oxygen therapy exercise bag;
FIG. 3 is a top view of the cylindrical oxygen therapy exercise bag; and,
FIG. 4 is a bottom view of the cylindrical oxygen therapy exercise bag.
The broken line showing of the cylindrical oxygen therapy exercise bag is for the purpose of illustrating portions of the article and forms no part of the claimed design.