How could physical activities and sleep influence affect inertia and affect variability? Evidence based on ecological momentary assessment

Engaging in physical activities or spending enough time asleep could bring sufficient benefits to individuals, especially influencing their affect. The study investigated the association between physical activities or sleep and affect inertia, and explored the relationship between physical activities or sleep time and affect variability. Using Ecological Momentary Assessment (EMA), students from a Chinese university (N = 96) were asked to answer a series of questions five times a day (at 9:00 a.m., 11:00 a.m., 3:00 p.m., 5:00 p.m. and 8 p.m.) for 7 consecutive days to report their different kinds of temporary affect states. Each subject was asked to wear a sports bracelet, which was used to record their amount of physical activities and the length of sleep each day. Contrary to the hypothesis, the result revealed that physical activities were significantly and positively associated with the affect variability of anxiety. The relationships between sleep time and any kind of affect variability were absent. As hypothesized, physical activities were negatively associated with affect inertia of anxiety, sadness, negative affect, activeness and interest, and sleep time was negatively associated with affect inertia of depression. These relationships could be explained by the characteristics of the subjects and physiology. The results show that physical activities and enough sleep are important in people's daily life. Limitations and implications for the present intervention and future research are discussed.