Does running on grass beat the treadmill? new study to find out

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Full-time college students aged 18 to 25 years old. * Healthy, with no history of major cardiovascular, respiratory, neurological, or endocrine diseases. * No exercise contraindications or injuries, capable of safely completing moderate-intensity running (treadmill, outdoor road, and grass running). * No recent major life events affecting physiological or psychological status (e.g., severe insomnia, anxiety, depression, or extreme fatigue). * No use of medications or supplements affecting heart rate, blood pressure, mood, or attention within the past week. * Normal or corrected-to-normal vision, capable of completing computerized cognitive tasks (e.g., Stroop, Go/No-Go, PVT). * Able to comprehend and truthfully complete psychological scales. * Voluntary participation and signed informed consent form. Exclusion Criteria: * Current or past diagnosis of severe cardiovascular disease (e.g., myocardial infarction, severe arrhythmia, uncontrolled hypertension). * Severe respiratory disease (e.g., severe asthma, COPD) or recent acute respiratory infection within the past month. * History of neurological disease or brain injury (e.g., epilepsy, recent concussion) affecting safety or cognitive task performance. * Endocrine or metabolic diseases (e.g., uncontrolled thyroid disease, severe diabetes) affecting cortisol or metabolic measurements. * Recent diagnosis or psychiatric treatment for severe psychological disorders within the past month. * Use of drugs or supplements affecting heart rate, blood pressure, cortisol, or attention within the past 7 days. * Currently pregnant or lactating. * Acute illness within the past 48 hours (e.g., fever, acute gastroenteritis). * Severe bleeding tendencies, blood disorders, or contraindications to blood/saliva sampling. * Recent substance use interference, such as heavy drinking or substance dependence within the past 2 weeks. * Inability to meet pre-experiment control requirements (e.g., avoiding caffeine, tobacco, or heavy exercise). * Inability to complete computerized tasks due to poor vision or lack of familiarity with keyboard/mouse. * Acute or chronic injuries hindering the safe completion of running intervention (e.g., recent lower limb injury). * Participation in similar HIT or environmental intervention studies within the past 3 months. * Unable to understand research procedures or unwilling to sign the informed consent form.