Many people think 'fast and long' is the answer to treadmill workouts, but I've experienced that pushing too hard often leads to weight loss plateaus and burnout. From a Traditional Korean Medicine perspective, the right approach depends entirely on your constitution and current condition. **A. If you have good stamina and digestion** – HIIT (e.g., 1 minute fast, 2 minutes slow, repeated) is effective for building muscle and increasing basal metabolic rate. However, be careful not to overstrain, which can cause Blood Stasis (eohyeol), leading to swelling and lingering fatigue. **B. If you often feel fatigued, have weak digestion, or tend to feel cold** – This is common among office workers. Start with low-intensity aerobic exercise (brisk walking, heart rate around 120 bpm) for 20–30 minutes. TKM calls this Spleen Deficiency (biheo). When the Spleen is weak, it cannot efficiently convert food into energy, so exercise may break down muscle instead of fat, leaving you more tired. Consistency and recovery are more important than intensity. Ultimately, you must first assess your current body condition before starting treadmill exercise to avoid wasted effort. It took me 10 years to realize this. Adjust exercise intensity based on your stamina and digestive health, and if needed, consider herbal medicine to address Spleen Deficiency or Blood Stasis for better results. The key is to work *smart*, not just hard.