Definition
A learning principle stating that things most often repeated are best remembered, and that practice strengthens the connection between a stimulus and a response while lack of practice weakens it. It is the underlying basis for the use of drill and practice as a teaching method.
Plain English
The more you do something, the better you remember how to do it. The less you do it, the more it fades.
Context Anchor
Seen in flight instructor training when discussing drill, practice, review, and why repeated correct performance matters in pilot training.
Derivation
Named after Edward L. Thorndike, an American psychologist (1874-1949) who studied how learning happens through trial and repetition. 'Exercise' here is used in its older sense of 'putting something into use' or 'practicing,' not physical workout.
Why Pilots Care
Instructors apply repetition during training to strengthen pilot responses to procedures and emergencies.
Intuition Check
Exercise does not mean physical workout here. It means practice: using a skill strengthens it, and leaving it unused lets it weaken.
Example Sentence 1
Following Thorndike's law of exercise, the instructor had the student run through the engine-failure checklist on every flight until the responses were automatic.
Example Sentence 2
Without regular practice, a pilot's ability to handle crosswind landings can weaken due to the effects described in Thorndike's law of exercise.