Objective To explore the accumulated effects of physical activity,sedentary behavior,and sleep on cardiorespiratory fitness(CRF)among college students and provide effective measures for enhancing their CRF. Methods From May to June in 2023,223 college students aged 18 to 24 years old were recruited from Tianjin University of Science and Technology for a 24 hours activity behavior survey and CRF testing.Compositional analysis was employed to investigate the relationships of physical activity,sedentary behavior,and sleep with CRF.Isotemporal substitution models were established to predict the effects of substituting various activity behaviors on CRF.Results The proportion of time spent on moderate-to-vigorous physical activity(MVPA)was positively correlated with CRF of college students(β=6.40,P=0.002),while the proportion of time spent on sedentary behavior was negatively correlated with CRF(β=-3.02,P=0.004).Light physical activity(LPA)and sleep were not correlated with CRF(β=-1.06,P=0.504).Isotemporal substitution results for 15-min increments showed that replacing other activity behaviors with MVPA significantly increased the CRF of college students[SB:1.72 mL/(kg·min),95% CI=0.94-2.51;LPA:1.82 mL/(kg·min),95% CI=0.95-2.68;sleep:1.64 mL/(kg·min),95% CI=0.84-2.45].In the dose-response relationship from -30 min to 30 min,reallocating time from other behaviors to MVPA had greater adverse effect on CRF than reallocating time from MVPA to other behaviors.Among all the substitutions,replacing LPA with MVPA had the most beneficial effect on improving CRF.Additionally,a 5-min increment was considered the optimal tipping point for MVPA replacing other activities.Conclusions This study underscores the importance of participating in MVPA for improving the CRF of college students.The isotemporal substitution model provides clear goals for the allocation of time for these behaviors,aiding in future intervention measure development and policy-making.
Humans ; Sedentary Behavior ; Sleep ; Students ; Cardiorespiratory Fitness ; Exercise ; Young Adult ; Adolescent ; Universities ; Male ; Female

Objective: To investigate the effects of ticagrelor on cardiorespiratory fitness in patients with coronary heart disease after percutaneous coronary intervention (PCI). Methods: A total of 1 073 patients, who were diagnosed as coronary heart disease and underwent cardiopulmonary exercise testing (CPET) within 1 year after PCI, were enrolled from September 2017 to September 2019 in Peking University Third Hospital, including 309 patients in ticagrelor group and 764 patients in clopidogrel group. Clinical information, blood test results, echocardiographic parameters, cardiorespiratory fitness related parameters (including peak oxygen uptake (VO(2)), anaerobic threshold VO(2), peak oxygen pulse (VO(2)/HR) and carbon dioxide ventilation equivalent (VE/VCO(2)) slope), coronary lesions and intervention information were obtained. Cardiopulmonary fitness related indexes were compared between the two groups, and the correlation between ticagrelor use and cardiopulmonary fitness related indexes was analyzed by multivariate logistic regression. Patients who underwent CPET within 1 month after PCI were included in the subgroup analysis. Results: In ticagrelor group, the age was (60.3±10.3) years, and 253(81.9%) cases were male. The age of clopidogrel group was (60.6±10.0) years, and there were 608(79.6%) males. No significant differences were observed in peak VO(2), anaerobic threshold VO(2), and peak VO(2)/HR between the two groups (all P>0.05), but the VE/VCO(2) slope was significantly higher in the ticagrelor group than in the clopidogrel group (30.075 (27.207, 33.603) vs. 28.853 (25.970, 32.336), P<0.001). Logistic regression analysis suggested that the peak VO(2), anaerobic threshold VO(2) and peak VO(2)/HR were not significantly correlated with the ticagrelor use (all P>0.05), while the VE/VCO(2) slope was independently correlated with ticagrelor use (OR=1.098, 95%CI 1.032-1.168, P=0.003). Subgroup analysis of patients who underwent CPET within 1 month after PCI also indicated that no significant difference were observed in peak VO(2), anaerobic threshold VO(2), peak VO(2)/HR and VE/VCO(2) slope between the two groups (all P>0.05). Logistic regression analysis suggested that the peak VO(2), anaerobic threshold VO(2) and peak VO(2)/HR were not significantly correlated with ticagrelor use (all P>0.05), while the VE/VCO(2) slope was significantly correlated with ticagrelor use (OR=1.132, 95%CI 1.030-1.244, P=0.010). Conclusion: Among coronary heart disease patients after PCI, treatment with clopidogrel does not result in significant decrease in exercise endurance as compared with patients treated with ticagrelor.
Aged ; Cardiorespiratory Fitness ; Exercise Test ; Female ; Heart Failure ; Humans ; Male ; Middle Aged ; Oxygen Consumption ; Percutaneous Coronary Intervention ; Ticagrelor

Noncommunicable diseases are the number one killer globally and it could develop due to various risk factors. This cross-sectional study was aimed to identify these risk factors by assessing body mass index, waist circumference, waist to hip ratio and blood pressure and to find out the correlation between these risk factors, and cardiorespiratory fitness and physical activity level. The study samples were 103 students from two universities in Negeri Sembilan state selected by the convenience sampling method. After ethical clearance, International Physical Activity Questionnaire-short form in English was used to assess the physical activity level. The cardiorespiratory fitness was assessed by the Rockport one mile walk test and the other parameters were assessed following the standard protocols. The percentage of overweight (32.04%) and pre-hypertension (25.24%) were higher among students. 35.92% of students reported a low physical activity level and 46.6% having a lower fitness level (fair and poor). The physical activity level correlated with the cardiorespiratory fitness level (P<0.01). The body mass index (P<0.01) and systolic blood pressure (male P 0.05, female P<0.01) negatively correlated with the cardiorespiratory fitness level. Therefore, measures have to be taken to improve the physical activity level and cardiorespiratory fitness to lower the risk of overweight and high blood pressure among university students.
cardiorespiratory fitness ; VO2 max ; Body mass index ; waist circumference ; Waist to hip ratio ; blood pressure