The Relationship Between Objectively Measured Cell Phone Use And Steps Over A 10-day Period

Abstract

Prior research indicates that cell phone use is a predominantly sedentary behavior. There is consistent evidence of a positive relationship between smartphone use and sedentary behavior. In other words, high daily cell phone use is associated with high daily sitting. However, while there is evidence that common smartphone uses (e.g., texting) performed during physical activity can reduce the intensity of that activity, the relationship between daily cell phone use and daily physical activity is equivocal. Much of the prior research assessing the relationships between cell phone use and physical activity has relied on self-repot survey instruments and there is a relative dearth of evidence assessing this relationship utilizing objective measures. PURPOSE: To assess the relationship between objectively measured cell phone use and physical activity. METHODS: Daily cell phone use (min) and daily physical activity (steps) were recorded for a period of 10 consecutive days in 50 college students (n = 23 female, 21.4 ± 3.3 years old). Data was obtained from software applications (i.e., apps) on the participants’ cell phones. For example, Apple iPhone users (n = 42 or 84% of the sample) used the “Screen Time” and “Health” apps to assess their cell phone use and steps, respectively. The relationship between these two variables was then assessed. RESULTS: Participants allocated 212.0 ± 76.7 min/day to cell phone use and accumulated 7091.4 ± 3270.8 steps/day. There was a near moderate effect size for the negative correlation between average cell phone use and steps (r = -0.25). In other words, as cell phone use increased, steps decreased. Mixed model regression demonstrated that the relationship between the cell use and physical activity over the 10-day period was significant (F = 17.6, p = 0.001). CONCLUSION: While the effect size of the inverse relationship between objectively measured daily cell phone use and steps was slightly less than moderate, it was statistically significant. This is different from prior research from our group and others who have not seen a significant relationship when using self-reported survey instruments to assess these variables. This difference highlights the need for additional research employing objective measures when assessing relationships between cell phone use and health behaviors.