Analysis of Objectively Assessed Physical Activity Patterns in American First-year Medical Students, During a Typical Workday

Abstract

The purpose of this study was to record the physical activity patterns of American first-year medical students whose daily schedules were known and virtually identical, and to examine the relationship of these activity patterns and BMI-derived weight classifications, among conditions of environmental influence on individual physical activity. Forty-six of 99 potential (46% participation rate) first year medical students completed the activity study in full, and 41 participants' data were included in the final analysis. Participant activity was recorded for a continuous 12-hour period, from 9:00 am through 9:00 pm, across a span of 11 weeks from August to October. The relationships of five activity variables and BMI-derived weight categories were examined across conditions of environmental influence. When environmental constraint upon participant activity was present, results indicated that BMI-derived weight category was positively related to sedentary fidgeting volume. When the environment did not constrain participant activity, relationships between BMI-derived weight categories and sedentary time (seconds), number of steps taken, stepping time (seconds), and stepping cadence (steps/min) were in the predicted direction, though none reached statistical significance. This study was the first of its kind to simultaneously quantify aspects of each of the three energetic components of daily energy expenditure: posture allocation, ambulation, and fidgeting.