A physicаl therаpist treаts a patient whо has a clоsed head injury and is in the cоnfused-agitated level of cognitive functioning. The therapist treats the patient in their home for 60 minute sessions, three times per week. Recently the therapist has noticed that the patient becomes increasingly combative as the session progresses and believes the deterioration in behavior is linked to the patient becoming fatigued. Which of the following treatment modifications is the MOST appropriate to assist in reducing patient fatigue?