A validated survey was administered to a random sample of students from a public US university (N = 226).
Mean self-reported cell phone use was 380 min day−1, 87% reported cell phone use primarily occurs while sitting, and 70% of use was for leisure. Cell phone use was positively related to sedentary behavior (β = 0.30, p < 0.001). It was not related to physical activity. However, the likelihood of cell phone use during moderate (p = 0.006) and mild (p < 0.001) intensity exercise increased as cell phone use increased.
Like other screens (e.g., TVs), cell phone use appears to be a sedentary leisure behavior. Furthermore, high frequency use increases the likelihood that it will occur during exercise, likely lowering exercise intensity.