Aerobic Exercise and Anaerobic Exercise
　　The so-called aerobic exercise is in contrast to anaerobic exercise. Aerobic exercise represents lightness and includes walking, cycling, playing tennis, golf, aerobic dance, long-distance swimming, etc. Anaerobic exercise represents effort and includes short-distance sprinting, weightlifting, high jump, long jump, javelin throwing, discus, sumo wrestling, etc.
　　The cells in our body take in oxygen through respiration and combine it with glucose nutrients to produce adenosine triphosphate (ATP). Muscles rely on ATP as energy to contract. Aerobic exercise produces ATP using oxygen while exercising, so we don’t feel extremely fatigued and can continue for a long time.
　　There are many benefits to aerobic exercise
　　First, it strengthens the heart. Aerobic exercises that repeatedly bend and extend the arms or legs moderately increase the heart's workload, preventing the decline of heart function.
　　Second, it prevents heart disease. Doing aerobic exercise continuously increases the number of capillaries in the heart, improving oxygen supply to the myocardium, preventing myocardial infarction, and increasing the chances of surviving a heart attack if one occurs. It also lowers cholesterol and softens blood vessels—benefits that are hard to achieve through anaerobic exercise.
　　Third, it’s suitable for weight loss. Long-term aerobic exercise does not reduce muscle mass but only burns fat. Fourth, it is a safe and feasible form of exercise. Especially for middle-aged and elderly people, it helps prevent sudden death.
　　Is aerobic exercise entirely beneficial?
　　So, aerobic exercise is said to be good for health, but the reality isn’t entirely so.
       Experts have conducted two animal experiments showing that excessive aerobic exercise can shorten lifespan. The first is about hibernating hamsters living longer, as published in a recent paper by Professor Hubert from Harvard Medical School in the U.S. He divided hamsters into three groups: those that hibernated well, those that hardly hibernated, and those in between, then compared their lifespans. The result was that the longest-lived hamsters who hibernated well lived up to 1600 days, while those that didn’t hibernate at all lived only up to 1100 days.
　　Hibernation can be said to be the exact opposite of aerobic exercise. As body temperature drops, oxygen consumption greatly decreases; conversely, excessive oxygen consumption clearly shortens lifespan. Another experiment showed that flies with high activity levels have shorter lives. This research, conducted recently by Dr. Sohar from the University of Southern Mississippi in the U.S., involved raising houseflies in large containers (27,000 cubic centimeters) and small containers (250 cubic centimeters) for comparison. The result was that flies in the large containers were very active, consuming 11.2 microliters of oxygen per milligram of body weight per hour, while those in small containers consumed 7.6 microliters. The flies in the large container, which consumed “a lot” of oxygen, lived for 33 days, while those in the small container lived for 78 days. This shows that higher activity and greater oxygen consumption lead to shorter lifespans.
　　Research also indicates that the results of aerobic exercise may lead to cancer, arteriosclerosis, Alzheimer’s disease, and can relatively be said to shorten lifespan.
　　In summary, when exercise becomes excessive and turns into a burden, aerobic exercise becomes “anaerobic exercise.” Exercising according to your physical condition is the key to staying happy and living longer.
　　When is the best time to exercise for fat burning?
　　Regarding fitness frequency, the American College of Sports Medicine recommends that normal individuals should work out 2–5 times per week. If you’re new to fitness, start with a small amount—twice a week—and gradually increase to three or four times. A common mistake beginners make is getting overly enthusiastic at the start, wanting quick results, and exercising every day with high intensity. This often leads to overtraining, resulting in fatigue, insomnia, and excessive soreness in a short time.
　　This then leads to quitting. In reality, we should understand that fitness is a long-term habit. To achieve a fit physique, one must maintain fitness throughout life. The best body shape and health condition require months or even years of consistency. Gradual progression is the best approach.
　　An average person burns about 15 kcal per minute of jogging (the more you weigh, the more you burn), and one kilogram of fat equals 3500 kcal. Jogging for 30 minutes a day, without changes in diet, can lead to losing one kilogram per week.
　　Of course, this is just theoretical calculation. In reality, people tend to eat a little more after exercising. Experts recommend a weight loss rate of half a kilogram per week, as weight lost this way is less likely to rebound.
　　Many people skip warm-ups to save time and go straight into high-intensity aerobic training. If so, because the cardiovascular system and lungs aren’t yet ready and body temperature is relatively low, along with poor muscle flexibility, injuries are more likely. Also, exercising after warming up feels better, and you can exercise for longer. In other words, exercising without warming up makes you more prone to fatigue.
　　Warming up generally refers to using low-intensity aerobic activity to gradually get your body ready—raising your body temperature slowly, increasing your heart rate, and making your breathing steady and faster. Blood circulation also speeds up, delivering oxygen and nutrients to your heart and muscles, preparing your body for exercise. An important sign that the warm-up is effective is when you start to break a slight sweat. Warming up for 5–10 minutes is sufficient. In cold weather, warm-up time should be longer, and you should wear more clothes.
Relaxation has the same effect as warming up. During exercise, blood circulation speeds up and blood volume increases, especially in the limbs. If you stop exercising abruptly, blood will pool in the lower limbs, putting extra strain on the heart. In severe cases, it can affect blood supply to the brain, causing dizziness or lightheadedness. Therefore, after achieving your exercise goal, you should have 5–10 minutes of relaxation—gradually reducing the intensity of exercise and slowly returning to a resting state.