1. Negative exercise
Some people believe that negative exercise will stretch the muscles and lengthen them. In fact, during the reduction process, the muscles are only relaxed and not stretched. The muscle is stretched only after reduction, caused by the pulling force of the weight. For example, in the suspension effect after the pull-up is restored, the chest muscles and upper back muscles are stretched by the pulling force of the own body weight; in the wing-spreading effect of the supine dumbbell fly, the chest muscles are stretched by the pulling force of the dumbbell weight; arm flexion and extension exercises of the upper arm and humerus After the biceps, triceps and forearm muscles are restored, etc. These reduced stretches have no growth effect on the muscles. The movement that really develops muscles is the compression effect of its positive exercise.
Some people think that you exhale when doing positive exercises and inhale when doing negative exercises. That is, exhale when exerting force and inhale when returning.
Inhaling during Zhenggong exercise (exerting force) can increase the amount of myoglobin for oxygen storage and muscle glycogen for energy supply, and expand muscle capillaries, which is conducive to exertion. If you exhale when exerting force, it will cause hypoxia and insufficient muscle glycogen energy supply, resulting in reduced muscle strength and the number of muscle fibers involved in exertion. In addition, insufficient “burning” of muscle glycogen will produce more lactic acid, causing muscle soreness and fatigue.
Those who advocate Zhenggong exercise require the movement speed to be 3-4 seconds and the recovery speed to be 2-3 seconds. Those who advocate negative exercise require the movement speed to be 2-3 seconds and the recovery speed to be 3-4 seconds.
In fact, the action speed is related to the load (proportional to it). Those with a small load will move faster, about 2-3 seconds; those with a larger load will move slower, about 3-4 seconds. So is the restore speed. Lifting speed that is too fast or too slow indicates that the weight being lifted is inappropriate.
2. Aerobic exercise
Aerobic exercise is based on heart rate. The maximum heart rate recognized by most people = (200-age) 80-90% is the upper limit, and 60-80% is commonly used. Exercise for 15-30 minutes each time to speed up blood circulation and promote metabolism.
With a normal heart rate of 70-80 beats per minute, the blood volume discharged by the heart per contraction is about 60 ml, with a total discharge of 4200-4800 ml per minute. According to the heart rate of aerobic exercise, the blood output of the heart per minute is about twice that of usual.
However, the higher the heart rate, the shorter the rest time of the myocardium, and the heart becomes fatigued easily. Moreover, when the heart rate is high, the time for the heart to relax may be too short to allow the blood to be completely filled, so when the heart muscle contracts again, the amount of blood discharged is reversed.And decrease. So simply raising your heart rate is not ideal. Even so, the purpose of heart rate-increasing exercise is to reduce the usual heart rate to about 60 beats per minute, thereby extending life. This is a new result in life science research. However, the increase in heart rate should be moderate to avoid excessive heart fatigue, which may cause myocardial strain and lead to heart disease. Long-term high-heart rate exercise (such as 10,000-meter running) is very harmful to health.
A better method is to increase the amount of blood pumped out by the heart with each contraction. For example, squats can effectively exercise the heart, causing the heart to produce strong contraction and relaxation forces. Therefore, appropriately accelerating heart rate and strengthening myocardial exercise are good strategies to improve the function of the circulatory system. In fact, the heart rate of strength training is not low, generally up to 120 beats per minute. For example, quick squats with light weight can achieve this purpose, which not only increases the heart rate, but also builds muscle lines?
The relationship between aerobic exercise and breathing shows that the depth of breathing has an impact on aerobic metabolism. A high heart rate means shallow breathing and less oxygen intake each time; a low heart rate means deeper breathing and more oxygen intake each time. It is best to take deep breaths while bearing weight (squats), which can exercise lung capacity. An increase in lung capacity is similar to an increase in cardiac output, meaning more oxygen is taken in and more carbon dioxide is expelled with each breath. Practicing deep squats for a long time can make your breathing deep and long when quiet, and the number of breaths per minute can be reduced to 8-10 times. Deep and slow breathing allows for a longer rest period after each breath, making it less likely to fatigue.