Clinical Research Directory

Inclusion Criteria: * Age between 20 and 45 years. * Body Mass Index (BMI) between 18.5 to 27 kg/m². * No sleep-related medical conditions and good sleep quality, defined as a Pittsburgh Sleep Quality Index (PSQI) score ≤ 5. * Usual bedtime between 22:00 and 01:00, wake-up time between 06:00 and 09:00, with an average sleep duration of 7 to 9 hours. Chronotype classified as "definitely not evening type" (score ≥ 42 on the Morningness-Eveningness Questionnaire), with no changes in sleep patterns over the past 3 months. * Without any metabolic or cardiovascular diseases, and not using medications that could affect metabolic responses. * No specific dietary habits, such as intermittent fasting or a ketogenic diet. * Maintaining a stable weight (no self-reported weight change greater than ±3 kg) for at least 3 months. * Resting blood pressure ≤ 130/80 mmHg. * No smoking or excessive alcohol consumption. * Not a shift worker. * No international travel across time zones in the past 3 months. Exclusion Criteria: * Special diets (e.g., intermittent fasting, ketogenic diet) * Recent injuries or contraindications to intense exercise.