A trainer is working with a client who is planning to begin a weekly exercise...

In the Stages of Change Model, NASM defines Preparation as: “The client intends to act in the near future, usually within the next month”. This stage is characterized by having a clear plan and intent to begin behavior change soon, possibly with some minor steps already taken (e.g., buying workout clothes or scheduling sessions). In this scenario, the client is “planning to begin a weekly exercise plan within the next month,” which exactly matches the preparation stage definition.

By contrast, Contemplation is thinking about starting in the next 6 months, Action is actively performing the new behavior (within the last 6 months), and Maintenance is sustaining the behavior for more than 6 months.