Author(s): JI, T., LUO, Y., LI, X., CAO, L., WANG, K., Institution: SHANGHAI JIAO TONG UNIVERSITY, Country: CHINA, Abstract-ID: 1793

Background: Enhancement of students’ affective outcomes is one of the primary goals of a physical education class. In outdoor settings, when high temperature and humidity occur together, the combined strain on the body's physiological and psychological systems are significantly magnified, which could likely intensify negative affect. This study aimed to explore the effects of air temperature and relative humidity on the relationship between exercise intensity and affective responses in a 16-week outdoor baseball class.
Methods: Thirty-three sophomore students in a 16-week outdoor baseball class participated in this study. ActiGraph GT3Xs were used to measure times spent in light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) throughout each class. The CLIMOMASTER device was used to measure air temperature and relative humidity every 10 minutes throughout each class. In the final five minutes of each class, students self-reported their affective states (feelings of revitalization, tranquility, positive engagement, and physical exhaustion) using the exercise-induced feeling inventory (EFI). Mixed-effect models were employed to analyze the relationship between LPA, MVPA, mean temperature, mean humidity, and affective responses.
Results: A significant three-way interaction effect of MVPA, temperature, and relative humidity was found on revitalization (b = -0.46, 95%CI = [-0.77, -0.14], p = 0.005) and positive engagement (b = -0.37, 95%CI = [-0.65, -0.10], p = 0.008). Simple slope analysis suggested that when temperature is below its median (23.3°C) and relative humidity is at or below its median (47.6%), an increase in MVPA is associated with a decrease in revitalization. When temperature reaches its highest value (31.0°C), the relationship between MVPA and revitalization is positive when humidity is at its lowest value (31.5%) and negative when humidity is at its highest value (75.6%). Regarding positive engagement, when temperature is at its lowest value (13.5°C) and humidity is below the median (47.6%), or when humidity is at its lowest value (31.5%) and temperature is below the median (23.3°C), the relationship between MVPA and positive engagement is negative. This relationship becomes positive when humidity is at its lowest (31.5%) but temperature reaches its highest value (31.0°C).
Conclusions: These results highlight the importance of adapting physical education class intensity based on environmental conditions. MVPA in cool and dry conditions may reduce feelings of revitalization and positive engagement, whereas MVPA in high temperatures combined with low humidity can actually enhance revitalization and positive engagement.