Why do people always say "exercise for 30 minutes"? Is 29 minutes enough?

The weather has been getting cooler recently, so we can no longer use the excuse of "I don't want to move because it's too hot" to avoid exercising. We are often advised to exercise for 30 minutes every day, but do we have to stick to it for such a long time to see the effect of exercise? Which exercise is better, aerobic exercise or anaerobic exercise?

01

What is the difference between aerobic and anaerobic exercise?

Aerobic exercise, in layman's terms, means that you can keep breathing smoothly throughout the exercise process, with sufficient oxygen to participate in energy supply. Aerobic exercise generally lasts for more than 15 minutes, with low intensity. Although our breathing is slow or rapid during the whole process, we can complete the breathing process smoothly.

Anaerobic exercise has a high intensity and a relatively short duration. During the entire exercise, there is no oxygen involved in energy supply , the heart rate increases rapidly, and it takes a long time to eliminate fatigue. For example, an athlete sprints 100 meters and usually crosses the finish line in about 10 seconds. The process of oxygen being inhaled into the body and generating energy takes time, and the oxygen inhaled at the start of the 100-meter sprint does not have time to participate in the energy supply of the sprint process before the exercise is over. Therefore, athletes have to breathe heavily after the 100-meter race.

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The aerobic exercises we usually engage in are mainly for fitness, and anaerobic exercises are mainly for body shaping, but the two do not exist independently. A fitness plan that reasonably combines the two can achieve better results in strengthening the body.

Difference Between Aerobic and Anaerobic Exercise

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02

Common aerobic and anaerobic exercises

For the general public, aerobic exercise is more applicable. It can help us lose fat and enhance cardiopulmonary function. It is also called "cardiopulmonary function training" and plays a vital role in the health of our body. So, what are some simple and practical aerobic exercises?

Jogging is the most popular aerobic exercise! All you need is a pair of running shoes that fit you well. You can run anywhere, anytime, on an indoor treadmill, in a residential area, in a park, or on a playground. Jogging can improve your body's metabolism, speed up the discharge of waste, prevent muscle atrophy, and enhance your cardiopulmonary function. Long-term jogging not only helps you lose weight and strengthen your body, but also relieves stress and soothes your mood.

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jump rope

Rope skipping can exercise muscles in multiple parts of the body at the same time, not only making muscle groups stronger, but also enhancing lower limb strength and joint ligament strength. If you skip rope for an hour every day, you can consume about 600 kcal of calories, which is favored by people who want to lose weight. However, skipping rope is not suitable for overweight or obese people, as it will increase the weight on the knees and damage the knee joints.

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Swimming only requires overcoming the resistance of water and is basically unaffected by gravity, which is incomparable to other land sports. It can protect our muscles and joints, especially the knee joints and lumbar spine. Obese people with excessive weight are prone to wear and tear of their knee joints when doing other land sports. Swimming is their best choice! In addition, swimming is an aerobic exercise in a cold water environment, which consumes a lot of calories and has a significant weight loss effect.

Image source: Photo Network - Traditional Chinese Fitness Exercise

Tai Chi, Ba Duan Jin, Wu Qin Xi, etc. are representative Chinese aerobic exercises. They are suitable for people who do not like strenuous exercise and prefer slow and elegant exercise, especially the elderly. These exercises are neither fast nor slow, with smooth breathing, focusing on physical exercise and internal energy conditioning. They are soft but firm, and can stretch muscles and bones and regulate emotions.

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Compared with aerobic exercise, anaerobic exercise is relatively monotonous. Full-speed running, barbells, dumbbells, squats, push-ups, weightlifting, plank support, etc. are all common anaerobic exercises.

Anaerobic exercise has a short duration for each set of movements, and often requires multiple sets of exercises to achieve the desired exercise effect. However, the exercise time cannot be too long, generally each set lasts no more than 2 minutes, 4 to 5 sets each time, and no more than 3 times a week. When doing anaerobic exercise, if the exercise intensity and time are unreasonable, it is easy to experience fatigue, joint injuries, muscle strain, resistance to exercise, etc.

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03

Does exercising for 30 minutes count as effective exercise?

The reason why there is a saying that "exercise for more than 30 minutes is effective" is mainly because exercise can only start to burn fat and achieve the effect of weight loss after a period of time. In fact , this statement has limitations, and the concept of "30 minutes" is not completely accurate because it does not take into account the method and intensity of exercise.

"One formula" teaches you to judge the intensity of exercise: target heart rate = (220-age-resting heart rate) × 60% + resting heart rate . The percentage in the formula represents the intensity. Less than 50% is a small amount of exercise, 50% to 75% is a medium amount of exercise, and more than 75% is a large amount of exercise. "Three tricks" to quickly and easily judge whether your exercise intensity is appropriate:

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1. Muscle soreness

During exercise, the body metabolizes to produce lactic acid, which accumulates in the muscles and causes soreness. Therefore, we often feel muscle soreness during exercise, which is normal. Massage and stretching can help relieve it.

2. Pain

If you feel pain in a certain part of your body during or after exercise, it may be that the tiny muscle fibers or ligaments in your body have been slightly damaged. At this time, you need to make appropriate adjustments, such as reducing the number of exercises or the range of motion, to help the body recover quickly.

3. Numbness

If you feel numbness in a part of your body after exercise, it means that there is a disorder in the body's sensory and motor functions, and continuing to exercise will damage the body. Therefore, once the body numbness occurs, you should rest in time. If it does not subside for a long time, you need to seek timely treatment. It is worth noting that no exercise is purely anaerobic or purely aerobic . Whether you choose aerobic or anaerobic exercise, choosing the exercise that suits you and sticking to it is the most important thing!

Author: Wang Hongping, Associate Chief Physician, Department of Endocrinology and Metabolism, Shanghai Putuo District Central Hospital

Editor: rain

Acknowledgements: Lei Tao, chief physician of the Department of Endocrinology and Metabolism, Shanghai Putuo District Central Hospital, provided scientific guidance for this article