How long does a heart rate of 120 last to burn fat

Maintaining a heart rate of 120 for 20-30 minutes can effectively burn fat, but the actual effect is affected by factors such as exercise intensity, individual metabolic differences, and exercise habits. Maintaining a heart rate of around 120 beats per minute during exercise belongs to the moderate intensity aerobic exercise range, during which the body mainly relies on fat oxidation for energy. For healthy adults, the fat breakdown efficiency significantly improves when the heart rate is maintained for more than 20 minutes, and reaches an ideal state after about 30 minutes. During the initial stage of exercise, glycogen is the main source of energy consumption, and as time goes on, the proportion of fat supply gradually increases to over 50%. It is recommended to use exercise methods such as variable speed running, swimming, cycling, etc. that can stably maintain the target heart rate.

Some special populations need to adjust the duration. People with poor cardiovascular function may experience a rapid increase in heart rate but insufficient actual exercise intensity. It is recommended to gradually increase the duration from 10 minutes. Long term fitness enthusiasts can increase their exercise intensity to 40 minutes at the same heart rate due to the high pumping efficiency of the heart. Pregnant women, middle-aged and elderly people, and other groups should prioritize intermittent exercise patterns to avoid the physical burden caused by maintaining a fixed heart rate continuously.

It is recommended to maintain a fat burning heart rate by combining dynamic stretching before exercise and static stretching after exercise to avoid muscle stiffness. Moderate hydration and high-quality protein supplementation after exercise can help with muscle repair and avoid a high sugar diet that offsets the fat burning effect. Regular monitoring of resting heart rate changes can evaluate the improvement of cardiopulmonary function. If persistent palpitations or prolonged recovery period occur after exercise, the exercise plan should be adjusted in a timely manner.