Objective: To explore the effects of a zerotime exercise (ZTEx) intervention on physical activity levels and sedentary behavior among college students, providing evidence for improving physical activity and reducing sedentary habits. Methods: In September 2023, 45 sedentary college students from a university in Fuzhou were recruited and randomly assigned to either the ZTEx group (23 students) or the control group (22 students) according to a random number table method. ZTEx group received two ZTEx focus group meetings for 3 months, while the control group received safety and health education. The International Physical Activity Questionnaire and a threeaxis accelerometer were used to evaluate the sedentary and physical activity levels of college students. At the same time, evaluations related to physical health and psychological questionnaires were completed. Mixed effects analysis of variance and nonparametric tests were used to statistically analyze the physical health, psychological questionnaire, and sedentary and physical activity data of the college students. Results: Postintervention, the ZTEx group showed significant improvements in the duration of lowintensity physical activity [pretest(1 492.78±369.50)min; posttest(1 918.93±354.63)min] and the number of sedentary interruptions [pretest(45.26±13.69)times; posttest(73.78±16.74)times]; grip strength [pretest(28.77±9.23)kg; posttest(31.78±8.00)kg]; sitting up continuously for 30 seconds [pretest(22.52±4.90)times; posttest(26.96±4.87)times]; general selfefficacy [pretest(26.52±4.14)points; posttest(32.96±5.24)points]; body composition summary [pretest(66.44±4.83)points; posttest(72.62±4.88)points]; and psychological composition summary [pretest(61.21±9.88)points; posttest(63.98±9.57)points], while reducing sedentary time [pretest(3 694.28±687.56)min; posttest(2 865.90±493.81)min] in the past 7 days, the differences were statistically significant(P<0.05). The control group exhibited no significant changes(P>0.05). Conclusion ZTEx effectively improve the lowintensity physical activity, increases sedentary breaks, and reduces prolonged sitting among college students, fostering healthier habits and improving physical/mental wellbeing.