From August to September 2022, a cross-sectional survey was conducted by using the convenience sampling method in Guangdong Province. Participants came from Jinan University, South China Normal University, Zhaoqing University, and Guangzhou Sport University, invite them to fill in the Physical Activity Scale, Pittsburgh Sleep Quality Index Scale (PSQI), Psychological Resilience Scale, and Social Adaptation Diagnostic Scale to collect data. The sample size is based on the rule of thumb, and all participants were informed and agreed to participate in the study. The main test was conducted by researchers majoring in psychology. Participants filled out questionnaires in the classroom and collected them on the spot. The answer time of each questionnaire was 5–15 min. A total of 1,689 students participated in the survey and 1,622 questionnaires were returned, with a valid recovery rate of 96.03%. The age range of the subjects was 18–23 years old, with an average age of 21.18 ± 1.518, of which 893 were male and 729 were female. A total of 395 were freshmen, 460 were sophomores, 398 were juniors, and 369 were seniors. The recruitment flow chart is shown in Figure 2.

The study has been approved by the Ethics Committee of Zhaoqing University and all processes follow the Helsinki Declaration.

To test the consistency of the data, the Harman Single Factor Test was used to test for common method bias in this study. The results showed that the variance explained by the first factor was 26.457%, less than the critical value of 40%. This shows that there is no common method bias in this study.

As shown in Table 1, the correlation coefficients of physical activity, sleep quality, psychological resilience, and social adaptation are statistically significant. Correlation analysis showed that physical activity was positively correlated with psychological resilience and social adaptation, and negatively correlated with sleep quality; there was a significant negative correlation between sleep quality and psychological resilience and social adaptation; there is a significant positive correlation between psychological resilience and social adaptation. The relationship between variables supports subsequent hypothesis testing.

As shown in Table 2, 55.06% (893 people) of the total sample are male and 44.94% (729 people) are female. The level of psychological resilience of boys was significantly higher than that of girls. There was no significant difference in physical activity, sleep quality, and social adaptation between boys and girls.

According to Ye and Wen’s (2013) suggestions on the test of intermediary effect, the model 6 in SPSS macro degree compiled by Hayes was used to complete the test of intermediary effect. The inspection results are shown in Table 3. First, controlling for demographic variables (gender and age), the direct pathway of physical activity on sleep quality was examined. The results showed that the model fitted well: χ²/df = 2.576, NFI = 0.935, GFI = 0.928, RMESA = 0.032, CFI = 0.904, and TLI = 0.951. The direct pathway of physical activity on sleep quality was significant before the inclusion of mediating variables (β = −0.2355, t = −9.8875, p < 0.01). Therefore, hypothesis 1 holds.

The role of psychological resilience and social adaptation in mediating the chain between the relationship between physical activity and sleep quality was then examined. The results showed that χ²/df = 2.630, NFI = 0.946, GFI = 0.913, RMESA = 0.050, CFI = 0.924, and TLI = 0.915, indicating a good model fit. As shown in Table 3, analysis of the main variable relationships indicated that the direct effect of physical activity on sleep quality remained significant after the inclusion of mediating variables (β = −0.0531, t = −2.8252, p < 0.01) and the remaining direct pathways all reached significant levels and could act on sleep quality through three indirect pathways: (1) physical activity → psychological resilience → sleep quality; (2) physical activity → social adaptation → sleep quality; (3) physical activity → psychological resilience → social adaptation → sleep quality. Hypothesis 2 was tested by the significant direct paths of physical activity on psychological resilience (β = 0.2145, t = 8.8225, p < 0.01) and psychological resilience on sleep quality (β = −0.3374, t = −15.7106, p < 0.01); the significant direct paths of physical activity on social adaptation (β = 0.1635, t = 7.7730, p < 0.01) and the direct pathway of social adaptation to sleep quality was significant (β = −0.4051, t = −18.5579, p < 0.01), hypothesis 3 was tested; the direct pathway of psychological resilience to social adaptation was significant (β = 0.5036, t = 23.9614, p < 0.01), indicating that a chain mediator of psychological resilience and social adaptation existed and hypothesis 4 was tested.

The deviation correction percentile Bootstrap method (repeated sampling 5,000 times) was used for inspection. It can be seen from Table 4 that the 95% confidence interval result of the intermediary effect Bootstrap: the confidence interval of physical activity → psychological resilience → sleep quality (−0.0977, −0.0503), and the intermediary effect amount is −0.0723; confidence interval of physical activity → social adaptation → sleep quality (−0.0929, −0.0453), and intermediary effect amount −0.0662; The confidence interval of physical activity → psychological resilience → social adaptation → sleep quality (−0.0613, −0.0296), the amount of intermediary effect is −0.0438, and the confidence interval does not include 0, indicating that the intermediary effect is significant. The mediating effect of psychological resilience and social adaptation between physical activity and sleep quality is shown in Figure 3.

This study shows that physical activity among college students can effectively predict sleep quality, which is consistent with previous relevant research results and verifies hypothesis 1 (Pedrosa et al., 2022). Merellano et al. (2022) concluded that being male and having a high level of physical activity during isolation is conducive to good sleep quality, regardless of age. Yao et al. (2022) believed that there was a significant correlation between physical activity and sleep. For those with sleep problems, it is recommended to increase moderate intensity physical activity to moderate and high levels. Previous research has shown that physical activity promotes mental health by secreting hormones such as dopamine (Archer et al., 2014). Reducing negative emotions can improve sleep quality (Zhao et al., 2020). The study also found that scientific and effective adherence to physical activity can reduce the level of serum cortisol and improve the body’s immunity, while the continuous improvement of sleep quality is closely related to the lower level of serum cortisol and immunity (Deng et al., 2018). Yang (2020) also pointed out that through aerobic training and aerobic combined resistance training, two kinds of exercise interventions can inhibit excessive arousal, regulate anxiety, tension and other negative emotions, and thus improve the quality of sleep. The study also found that resistance training can promote the release of IL-6 from skeletal muscle for immune regulation, which can improve the quality of sleep to a certain extent. However, some researchers have proposed that the level of physical activity will have a negative impact on sleep quality, such as physical activity with too high intensity or too late. Therefore, when increasing the amount of physical activity is used to improve sleep quality, attention should still be paid to selecting the time and intensity of physical activity.

This study found that psychological resilience played a mediating role between physical activity and sleep quality, which verified hypothesis 2. This is consistent with previous relevant research evidence, that is, physical activity significantly positively predicts psychological resilience and psychological resilience significantly negatively predicts sleep quality (Xu, 2018; Zhang et al., 2021). This study included three variables at the same time, revealing that physical activity is an important factor in promoting psychological resilience and improving sleep quality.

On the one hand, psychological resilience has a negative predictive effect on sleep quality. Psychological resilience is characterized by the ability to recover from stress, which is critical to sleep quality. According to the neuroscience theory of resilience, resilience plays a mediating role in the relationship between middle front gross (MFG) functional connectivity and sleep quality, providing new insights into the relationship between resilience and sleep quality (Yan et al., 2022). The neural mechanism of psychological resilience also believes that psychological resilience is related to brain regional structure, neural circuit, and brain neural network, and brain function plays an important role in emotional regulation, thus indirectly affecting sleep quality (Yang et al., 2019). The protective mechanism of psychological resilience believes that the better the individual’s psychological resilience is, the better he or she will be able to cope with the adversity in learning and life, reduce the impact of negative stress events on himself or herself, face problems in a positive way, and promote the development of physical and mental health. Therefore, as an important psychological resource, psychological resilience plays a protective role in sleep quality (Babak et al., 2021).

On the other hand, physical activity positively predicted psychological resilience. The entertaining, open and competitive characteristics of sports situation provide a better space for the development of college students’ psychological resilience. In the related research on the development of psychological resilience, physical exercise is regarded as an important influencing factor. Regular physical exercise can improve psychological resilience, including reducing physical and psychological responses to stress, improving individual physiological and psychological status, and acting as a buffer for stress (Belcher et al., 2020). The prevention model of psychological resilience development believes that every kind of pressure that is not too strong is a challenge to the individual, but it can also enhance psychological resilience after the pressure is overcome (Yang et al., 2019). In the process of physical activity, college students will encounter the pressure related to learning sports skills, challenges from competitors and the sense of frustration brought about by them. These may not be conducive to the mental health of college students in the short term. However, after successfully overcoming these problems through their own efforts or with the support of their peers and teachers, they can form a more flexible attitude and improve their ability to solve problems, then they can effectively cope with and adapt to the situation of passion in life, and maintain a positive attitude toward life and emotional state. Sports have diversified functions. Physical activity can not only improve the physical and mental health of college students, but also an important way to enhance their will quality (Pan and Yu, 2015). Through physical activity, students’ attention orientation can be adjusted, their cognitive function can be improved, and their emotional regulation level can be improved, which are all related to the internal forming factors of their psychological resilience (Liu, 2020). Therefore, physical activity can improve the development of sleep quality by enhancing students’ psychological resilience.

This study also found that social adaptation plays a mediating role between physical activity and sleep quality, which confirms hypothesis 3 of this study. This is consistent with previous relevant research evidence, that is, physical activity positively predicts social adaptation, and social adaptation further predicts sleep quality (Wang, 2011). This study included three variables at the same time, revealing that physical activity is an important factor to improve individual social adaptation, and also an important factor to improve sleep quality.

There is a significant negative correlation between college students’ social adaptation and sleep quality. Research shows that sleep quality is positively related to stress, negative coping, and negative emotions (Li, 2021). Individuals with higher social adaptability also have higher sleep quality. The possible reason is that college students with good social adaptability not only include the ability to adapt to practical work with the book knowledge they have learned, but also include the ability to coordinate interpersonal relationships and living environment harmoniously. Individuals with this ability can keep good contact with the natural environment and social environment, and have good adaptability to the surrounding environment. They have certain communication ability, can effectively cope with the pressure of daily life and work, and can work, study and live normally. When individuals face setbacks and failures or sudden stress events, they can take appropriate behavior without excessive stress reaction and have strong self-regulation ability. All these important psychological resources are important internal resources for overcoming sleep disorders and thus are more conducive to improving their sleep quality (Yuan et al., 2015).

The study confirmed that physical activity was a causal variable for adolescents’ social adaptation, i.e., adolescents’ physical activity significantly predicted later social adaptation, and the results were generally consistent with Sun et al. (2019). The theory of socially adaptive development suggests that human society develops based on continuous learning and exploration of life practices. It follows that physical activity, as a positive social interaction activity, can create an opportunity for young people to interact with each other and with society, enabling them to exchange emotions with their peers, build a wider interpersonal circle, and enhance their social adaptation skills (Chen and Yu, 2015). As a type of challenging social practice, physical exercise is often accompanied by difficulty, task challenge, self-improvement and goal attainment, enabling individuals to continuously experience learning, coping and self-representation in exercise practice, achieving a balance between themselves and the environment through assimilation and adaptation, and enhancing their ability to deal with and adapt to situations. Regular physical exercise not only strengthens the body and builds the personality, but also enables young people to stimulate their sense of teamwork, develop interpersonal communication skills and enrich their skills and techniques in handling and solving problems through the practice of physical exercise, so as to improve their overall social, handling and interpersonal relations and other social adaptation skills and reduce externalized problem behaviors (Bornstein et al., 2010). It is for this reason that we should urge and encourage young people to be physically and mentally active in order to enhance their social adaptation.

This study found that college students with higher levels of psychological resilience had greater social adaptation. Adaptation is the interaction between an individual and his or her environment during the process of growth, and is manifested in dynamic changes in emotions, cognition and behavior, in which the individual constantly adjusts his or her adaptive state according to the environment. Psychological resilience is an important protective factor for mental health (Zhang and Tian, 2014). The higher the level of psychological resilience, the more psychological resources an individual has, the more he is able to mobilize and allocate his psychological resources, such as optimism and strength, according to the environment, in order to recover from negative experiences and adapt flexibly to the external environment. The Dynamic Model of Psychological resilience suggests that psychological resilience is an innate ability of individuals who need to meet their own needs for security, belonging, love and respect as they grow up, and that the material and spiritual support they receive from family, peers and society during physical activity is an important resource for meeting these needs. If these external protective factors meet the individual’s psychological needs, the individual will actively develop his or her own good traits, improve his or her psychological resilience and social adaptation, and thus improve the quality of his or her sleep. Therefore, the higher the level of physical activity of college students, the more social support they receive, i.e., the more care, support and assistance they receive from their parents, friends and teachers, etc., the higher their level of self-confidence, the lower their level of anxiety and depression, the better their psychological resilience, the better they are at mobilizing all kinds of resources to actively cope with setbacks, difficulties and environmental changes and other aspects of stress, promoting improved social adaptation and eliminating sleep. The higher the level of self-confidence, the better the college students will be at mobilizing resources to cope positively with frustration and stressful situations such as environmental change, promoting social adaptation, and eliminating sleep disorders.

The present study examined the effects of physical activity on sleep quality, enriching related research in the field of physical activity and sleep quality with practical implications for improving sleep quality among college students. First, physical activity is an important predictor variable not only of sleep quality, but also of psychological resilience and social adaptation. According to current research evidence, sleep problems among college students are increasing, and physical activity can be an adjunct to non-pharmacological interventions to improve sleep quality. Therefore, physical activity should be encouraged and supported to develop good lifestyles and habits in order to improve the sleep problems of Chinese college students. It is recommended that college students pay attention to the selection of physical activity programs, intensity, time, and frequency, so that they can be persistent and challenging, and that they can improve their social adaptation and psychological resilience in the process of physical activity in order to prevent and reduce sleep quality problems more favorably. Secondly, psychological resilience and social adaptation are important factors influencing the quality of sleep of college students. The mediating role of psychological resilience and social adaptation suggests that university educators should pay attention to the impact of psychological resilience and social adaptation on the sleep quality of college students and use psychological resilience and social adaptation growth group counseling interventions to improve the level of psychological resilience and social adaptation of college students, to improve their ability to cope with stressful events, to be able to look at problems in an objective and rational manner, and to be proactive in adapting to life, school and work. This will enhance the effect of physical activity on the quality of sleep of college students and reduce their sleep quality problems.

Firstly, this study used a self-report questionnaire, and data could be collected in the future using a combination of others’ ratings and self-reports. Secondly, this study adopted a cross-sectional research method to explore the mechanisms of physical activity on sleep quality among college students, but this research method could not draw inferences about the causal relationships between variables, and future in-depth research could be conducted using a longitudinal follow-up or experimental intervention design. Future research could focus on different types of universities in different regions to further validate the findings of this study. Finally, this study only considered the mediating effect of psychological resilience and social adaptation between physical activity and sleep quality, while there may be other mediating variables such as perceived stress and social support that need to be investigated in depth.