Protective effect of Glycyrrhizin on cuprizone-induced model of multiple sclerosis in male C57BL/6 mice.

The college period represents a transitional stage from late adolescence to early adulthood, during which individuals gradually achieve physiological maturation, psychological independence, and the formation of autonomous lifestyles and behavioral habits. College students constitute a major population of internet users and, simultaneously, a high-risk group for internet-related problematic behaviors (). Problematic internet use refers to a pattern of excessive and persistent internet engagement characterized by strong cravings and loss of control, resulting in significant psychological, physiological, and social functional impairments (, ). Problematic short video use, problematic social media use, and problematic internet game use are commonly used indicators for assessing levels of problematic internet use among college students (). Specifically, problematic short video use is primarily manifested as compulsive consumption of short video content and emotional dependence; problematic social media use emphasizes excessive involvement in online social interactions and difficulties in behavioral control; problematic internet game use is characterized by immersion in online or offline games, accompanied by pronounced withdrawal symptoms and impairments in real-life functioning (). A growing body of research indicates that these forms of problematic internet use may exacerbate disruptions in biological rhythms among college students. For example, problematic short video use may lead to delayed sleep onset and reduced sleep quality, thereby impairing the regularity of daytime activity rhythms. Problematic social media use not only disrupts sleep rhythms but may also interfere with dietary rhythms and daily activity schedules through excessive immersion and instant feedback mechanisms. Problematic internet game use can affect multiple dimensions of biological rhythms, including irregular daily routines, delayed meals, and reduced physical activity (, ). Given that the college period is not only a critical stage for the rapid development of problematic internet use but also a key window for mental health intervention (), identifying effective strategies for the prevention and regulation of problematic internet use among college students has become a central research focus across interdisciplinary fields such as education and psychology. According to Self-Regulation Theory, the occurrence and maintenance of problematic internet use are closely associated with insufficient self-control capacity and a preference for immediate rewards. As a modifiable lifestyle behavior, physical activity (PA) is hypothesized to be associated with problematic internet use, and this relationship may potentially relate to psychological and behavioral processes linked to self-regulation, which remains to be empirically examined in future research (, ). Previous studies have examined the associations between physical activity and different forms of problematic internet use, with findings consistently indicating that higher levels of physical activity are significantly negatively correlated with problematic short video use, problematic social media use, and problematic internet game use (, ). However, there is currently no consensus regarding the strength thresholds and scope of effects of physical activity level on problematic internet use. Some studies suggest that moderate or higher levels of physical activity are sufficient to exert positive effects, whereas others indicate that only high levels of physical activity can significantly reduce the risk of addiction. Still other studies have reported that even low levels of physical activity may alleviate certain forms of problematic internet use (). Therefore, a more systematic examination of the effects of different physical activity levels on the risk of problematic internet use among college students is warranted to clarify these inconsistencies.