High-Intensity Interval Training Across Exercise Environments: Acute Effects on Physiological Stress, Cardiovascular Responses, Executive Function, and Psychological Experience

The goal of this clinical trial utilizing a randomized crossover design)is to explore the modulating effects of different exercise environments （green parks, outdoor athletic tracks, and indoor settings) on acute responses to High-Intensity Interval Training (HIIT). It aims to determine if environmental factors can optimize an individual's stress regulation, cognitive improvement, and psychological exercise experience. The study involves 25 healthy full-time college students aged 18 to 25. The main questions it aims to answer are： 1. Are there significant differences in physiological stress (e.g., salivary cortisol, HRV) and cardiovascular responses when performing HIIT in different exercise environments (indoor, track, park)? 2. How does the exercise environment influence executive function (inhibitory control and cognitive flexibility) and subjective psychological experiences (e.g., emotional state, enjoyment, and exercise motivation) following HIIT? Researchers will compare the performance of participants across three conditions-Green Park (natural environment), Outdoor Athletic Track (conventional outdoor environment), and Indoor Venue (artificial environment)-to identify the modulating effects of different environments on exercise outcomes. Participants will ： Sign the informed consent form and complete baseline health screenings and psychological scales. Undergo resting physiological measurements (Heart Rate, Heart Rate Variability, Blood Pressure, Salivary Cortisol) and complete computerized executive function tasks (Stroop task and More-odd-shifting task). Perform approximately 15 minutes of standardized preparation activities (warm-up). Complete a 15-minute high-intensity interval jump-rope training session (using a protocol of 30 seconds of high-intensity exercise followed by 30 seconds of recovery) in a randomly assigned environment. Immediately following the exercise, undergo repeated physiological measurements, psychological assessments, and cog