Running fast vs. slow: Which is better for weight loss?

A debate is ongoing in Vietnam regarding the optimal running pace for weight loss, with some claiming that slow running is more effective for burning fat, while fast running primarily burns carbohydrates. However, experts emphasize that the human body continuously utilizes a combination of fat and carbohydrates for energy, regardless of exercise intensity. During low-intensity exercise, the body burns a higher proportion of fat. As intensity increases, the body is compelled to increase its reliance on carbohydrates, which supply energy more rapidly. This transition is gradual and continuous, rather than an abrupt switch. The true value of running extends beyond mere fat burning to include metabolic improvements and endurance building. Conversely, during high-intensity runs or competitions, significant depletion of glycogen stores can impair the body's ability to maintain blood glucose levels, leading to exhaustion and difficulty concentrating. To run effectively and protect one's health, balancing exercise intensity with proper nutrition is crucial. Instead of assuming that running to exhaustion leads to faster progress, individuals should develop workout plans with clear goals, incorporating rest intervals and light runs for recovery. For continuous exercise lasting 60 to 90 minutes or longer, replenishing carbohydrates is essential. During a 1- to 2.5-hour run, approximately 30-60g of carbohydrates per hour is recommended. This figure can increase to 60-90g per hour for runs exceeding 2.5 to 3 hours, depending on intensity and absorption capacity. It is generally recommended to engage in at least 150 minutes of moderate exercise per week. Activities such as walking, jogging, gym workouts, or yoga can be chosen based on personal preferences and physical condition. The ideal time for workouts is between 4 p.m. and 7 p.m., which aids in weight loss and muscle toning. Time after 9 p.m. should be reserved for rest. Even for healthy individuals or those with extensive training experience, listening to one's body is paramount. When feeling tired, drained, or short of breath, stopping to rest is advisable rather than pushing through. Prolonged late-night training sessions, even for healthy individuals, can lead to muscle atrophy, long-term mobility impairment, and irreversible joint conditions.