Do not allow the instructor to deliver a monologue any longer than 15 minutes before changing delivery technique or requiring an activity. 15 minutes is often the threshold where students lose interest in listening, especially if the subject matter is dry.
Incorporate different presentation methods into your training materials. For example, the instructor can introduce a topic, and then ask the students to discuss, or the instructor can demonstrate a method of accomplishing a task, and then have the students perform the task.
Use blended learning techniques in the training materials. For example, show a video rather than talking about a situation or task. Develop interactive e-learning applications that can be performed "hands on" in the classroom during training.
Break the students into groups and have the groups complete tasks or play games that reinforce the lesson plan. When possible, have the groups stand and work on white boards or chalk boards to get them out of their chairs.