Ambulatory 24-hr esophageal pH monitoring is considered the gold standard for diagnosing gastroesophageal reflux disease (GERD). The current approach is to encourage patients to pursue their everyday activity in order to obtain near-physiological recordings. However, the effect of the test itself on reflux-provoking activities has never been evaluated. Thus, the aim of our study was to assess daily food consumption, habits, symptoms, sleep, and perceived experience of patients undergoing pH testing as compared to an off test (normal) day. Patients reported type and time spent in each activity pursued, food ingested and length of each meal, habits, frequency and severity of GERD and other related symptoms, sleep disturbances, side effects, and overall perceived experience during pH testing and four weeks later, during a normal day. Fifty-four patients enrolled. pH testing significantly reduced time spent being active, number of meals and cups of coffee consumed, and frequency of GERD symptoms. Almost half of the patients reported having dysphagia during the test. Most patients experienced side effects and stated that the test bothered them most of the time. In conclusion, pH testing has a significant effect on decreasing reflux-provoking activities-patients tend to assume a more sedentary lifestyle. This may influence the reliability of the test as a physiologic measure of acid reflux.