Park vs. gym: study tests if green spaces boost HIIT benefits

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 lower limb injuries, able to safely complete high-intensity interval training (including jump rope). * No recent events affecting physiological or psychological status, such as severe insomnia, anxiety, depression, or extreme fatigue. * Have not taken medications or supplements affecting heart rate, blood pressure, mood, or attention in the past week. * Normal vision or corrected-to-normal vision, capable of smoothly completing computerized cognitive tasks. * Able to comprehend and truthfully complete psychological questionnaires. * Voluntarily participate, fully understand the research procedures, and sign the informed consent form. Exclusion Criteria: * Severe cardiovascular diseases (e.g., myocardial infarction, severe arrhythmias, uncontrolled hypertension). * Severe respiratory diseases (e.g., severe asthma, chronic obstructive pulmonary disease, or recent acute respiratory infections). * History of neurological diseases or brain injuries (e.g., epilepsy, recent concussion) that may affect safety or cognitive tasks. * Uncontrolled endocrine or metabolic diseases that may interfere with cortisol or metabolic measurements. * Severe psychological disorders or receiving psychiatric treatment in the past month. * Use of drugs or supplements significantly affecting heart rate, blood pressure, cortisol, or attention in the past 7 days. * Currently pregnant or lactating. * Acute illness in the past 48 hours (e.g., fever, acute gastroenteritis). * Severe bleeding tendencies or blood disorders, unable to provide biological samples. * Substance use interference, such as heavy drinking or substance dependence in the past 2 weeks. * Unable to meet pre-experiment control requirements (e.g., avoiding caffeine, heavy exercise, tobacco). * Unable to complete cognitive tasks (e.g., poor vision, inability to use a keyboard/mouse). * Injuries or conditions limiting the safety of HIIT (e.g., recent severe lower limb injury). * Participation in similar HIIT environmental intervention studies within the past 3 months. * Insufficient ability to give informed consent or unwilling to sign the consent form.