The relationship between physical activity and subjective well-being in Chinese university students: the mediating roles of perceived health, social support and self-esteem.

Purpose: The intent of this paper is to understand the effect of Physical Activity on university students' Subjective Well-being and to explore whether Perceived Health, Social Support, and Self-esteem play roles as mediating variables. Methods: Self-reported data from 404 college students (147 males and 257 females) were analyzed using structural equation modeling (SEM). The relationships between the study variables were tested by mediation models and 5,000 bootstrap samples using AMOS version 24. Results: (1) The six hypotheses were supported in the measurement model in the results (P < 0.05). Physical Activity was related to Social Support, Perceived Health, and to Self-esteem; Social Support, Perceived Health, and Self-esteem were all related to Subjective Well-being. However, the direct positive effect of Physical Activity gradually decreased in the order of Self-esteem, Social Support, and Perceived Health. The direct effect of Perceived Health, Social Support, and Self-esteem on Subjective Well-being also decreased sequentially. (2) In the Structural Equation Model (χ2 = 825.451, p < 0.001, df = 455, CMIN/df = 1.814, CFI = 0.942, RMSEA = 0.045), the three hypotheses of mediation were supported (P < 0.05), showing positive indirect effects between Physical Activity and Subjective Well-being. Of the three mediating effects, Social Support and Self-esteem were not different, and the mediating effect of Perceived Health showed the largest impact. This indicates that Social Support, Perceived Health, and Self-esteem mediate the effects of Physical Activity, and Subjective Well-being regulation has positive indirect effects. Conclusion: This study demonstrates the importance of meeting the needs of Social Support, Perceived Health, and Self-esteem when designing interventions to promote college students' sports participation to enhance Subjective Well-being.

Distribution of Bioelectrical Impedance Vector Analysis and Phase Angle in Korean Elderly and Sarcopenia.

PURPOSE: This study aimed to verify whether bioelectrical impedance vector analysis (BIVA) can support the clinical evaluation of sarcopenia in elderly individuals and evaluate the relationships between phase angle (PhA), physical performance, and muscle mass. METHODS: The sample comprised 134 free-living elderly individuals of both sexes aged 69-91 years. Anthropometric parameters, grip strength, dual-energy X-ray absorptiometry findings, bioimpedance analysis results, and physical performance were also measured. The impedance vector distributions were evaluated in elderly individuals using BIVA. RESULTS: BIVA revealed significant differences between the sarcopenia and non-sarcopenia groups (both sexes). The sarcopenia group had a significantly lower PhA than the non-sarcopenia group in both sexes (p < 0.05). PhA was significantly correlated with age, appendicular skeletal muscle (ASM), handgrip strength (HGS), and muscle quality in both sexes and significantly correlated with ASM/Height2 and physical performance in males. CONCLUSION: BIVA can be used as a field assessment method in elderly Koreans with sarcopenia. PhA is a good indicator of muscle strength, muscle quality, and physical performance in males. These methods can help diagnose sarcopenia in elderly individuals with reduced mobility.

Accuracy of Estimated Bioimpedance Parameters with Octapolar Segmental Bioimpedance Analysis.

The validity of the impedance parameters of the five body segments estimated using octapolar segmental bioelectrical impedance analysis (OS-BIA) has not been confirmed. This study aimed to verify the accuracy of the resistance (R), reactance (Xc), and phase angle of each five-body segment. The accuracy of the OS-BIA at 50 kHz was measured based on the direct tetrapolar segmental BIA. The differences in the estimated impedance parameters of the five body segments were compared to those measured from the OS-BIA in elderly men (N = 73) and women (N = 63). The estimated 50 kHz-R (Ω) was significantly higher than the measured 50 kHz-R in the right and left arms, and lower than the measured 50 kHz-R of the trunk, right leg, and left leg (all, p < 0.05). The estimated 50 kHz-phase angles in all the five body segments were significantly lower than the measured ones (all, p < 0.05). The findings suggest that the estimated impedance parameters, R, Xc, and phase angle of the trunk, were remarkedly underestimated, limiting the assessment of the physiological state of the organs in the body. Therefore, further intensive research is needed in the field of estimated segmental BIA in the future.

The Development of a Model to Predict Sports Participation among College Students in Central China.

This study applies the theory of planned behavior (TPB) and self-determination theory (SDT) to predict the sports participation and exercise intentions of college students in Central China by considering the mediating roles of attitudes, subjective norms, and perceived behavioral control. Structural equation modeling (SEM) was used to analyze self-reported data from 294 college students (144 males and 150 females). The relationship between the research variables was tested by the mediation model and Bootstrap 5000 sampling using AMOS version 24. The results show that the direct effects of attitudes and perceived behavioral control on motor intention and motor participation are significant in the model. The satisfaction of the three psychological needs had a positive indirect effect on motor participation through attitudes; competence and autonomy had a positive indirect effect on motor participation mediated through subjective norms; however, only competence had a positive indirect effect on motor mediated through perceived behavioral control. In conclusion, this research demonstrates the importance of meeting these three basic psychological needs when designing intervention measures to promote college students' sports participation.