1. A training system that trains an exercise using poses with the body, the training system comprising: a reproducing device; and a recording medium installed on the reproducing device, wherein the reproducing device is a portable type, and includes a display unit, a notification unit, and a computer for controlling the units, the recording medium is readable by the computer included in the reproducing device, and includes an elementary pose data storage unit that stores elementary pose data which is used to display a plurality of elementary poses on the display unit, a simple pose data storage unit that stores simple pose data which, for each elementary pose, is used to display simple poses having lower difficulty level than the elementary pose, and a breathing timing data storage unit that stores timing data which is notified by the notification unit for each of the elementary poses and the simple poses, and the recording medium has recorded thereon a program which causes the computer to execute the steps of causing the display unit to display an elementary pose on the basis of the elementary pose data, and causing the notification unit to notify a breathing timing corresponding to the elementary pose on the basis of the breathing timing data, in a state in which the elementary pose is displayed on the display unit in the step of causing the display unit to display the elementary pose, detecting presence/absence of a predetermined operation, when the predetermined operation is detected in the step of detecting the predetermined operation, reading out, from the simple pose data storage unit, simple pose data corresponding to a simple pose, which corresponds to the elementary pose displayed on the display unit, and reading out, from the breathing timing data storage unit, breathing timing data corresponding to the read simple pose data, and causing the display unit to display the simple pose on the basis of the simple pose data read in the step of reading out the simple pose data, and causing the notification unit to notify a breathing timing corresponding to the simple pose on the basis of the breathing timing data.