The causative mechanism of fatty liver is complex, involving lifestyle habits, dietary habits, and family genetic predisposition, so the disease emphasizes comprehensive treatment. Among them, too much energy intake and too little consumption are the main causes of fatty components deposited in liver cells, so in addition to diet therapy, it is also very important to carry out standardized exercise therapy in a scientific and reasonable way.
When exercising, the metabolism of liver and muscles is greatly enhanced, which makes energy consumption greatly increased, forcing more fat decomposition on the one hand, accelerating the oxidation and utilization of free fatty acids, thus reducing the content of free fatty acids, and on the other hand, accelerating the utilization of sugar, lowering blood sugar, thus reducing the conversion of sugar to fat and reducing the synthesis of fat in the liver. Therefore, exercise not only enhances physical fitness, but also reduces blood pressure, blood lipids and body weight, controls blood sugar, and treats other predisposing causes (such as obesity, hyperlipidemia and diabetes).
Studies have shown that high-intensity regular exercise is associated with low fat composition in the liver. After administering six months of exercise therapy to 20 patients with nonalcoholic fatty liver disease, one scholar found that after six months of sustained moderate-intensity exercise, patients lost weight, all patients had improved liver function, and the CT imaging liver/spleen density ratio increased.
Exercise therapy for fatty liver should pay attention to the following aspects.
1.Exercise modality
Exercise therapy for fatty liver should be based on aerobic exercise. Aerobic exercise is to participate in the body’s large muscle groups, exercise intensity is lower, longer duration, regular exercise, this kind of exercise through aerobic metabolism for energy, is endurance exercise, to the whole body locomotor exercise mainly, local static exercise as a supplement, exercise method is simple and easy. In full consideration of personal exercise habits and preferences, the type of exercise as well as the loss of interest in exercise.
As each person’s lifestyle, work characteristics, exercise habits, hobbies, their own exercise base conditions, the current liver function situation, etc. are different, and therefore the exercise program is different. Exercise prescription must reflect the principle of individualization.
Aerobic exercise is often divided into two categories: the first type of exercise intensity and heart rate change is not large, easy to adhere to, such as walking, jogging, swimming, bicycling, etc.; the second type of exercise intensity and heart rate change is large and not easy to maintain, such as dance and games, etc.. Can be selected according to their own conditions, interests and so on. Research shows that in the common sports competition, 300m running, 5000m running, marathon running, 1500m swimming, cross-country running, skiing, road cycling, race walking, etc. are aerobic sports.
2.Exercise intensity
The greater the amount of exercise is not the better the therapeutic effect achieved, but the appropriate exercise can achieve good therapeutic effect.
In the evaluation of aerobic exercise, the maximum oxygen uptake (VO2max) is commonly used as a comprehensive index to evaluate the aerobic work capacity of human body, which refers to the amount of oxygen that human body can take in per unit of time when the heart pump function and oxygen capacity of muscles in the oxygen transport system reaches its limit level during the exhaustive exercise in which a large number of muscle groups participate. Studies have shown that during low-intensity exercise (25% VO2max), peripheral lipolysis is strongly stimulated, and despite the breakdown of a small amount of muscle triglycerides, the body’s energy supply is mainly provided by blood sugar, and muscle glycogen is rarely used.
In medium-intensity exercise (65% VO2max), the proportion of energy supply accounted for by fat oxidation is the highest, at this time, all fat decomposition from peripheral fat cells and muscle triglyceride reserves, and reached its highest degree. However, when the exercise intensity reaches 85% VO2max, the rate of fat release into the blood is inhibited due to the elevation of catecholamines in the blood circulation caused by intense exercise, which stimulates muscle glycogenolysis and glucose uptake.
So when the exercise intensity increased from 65% to 85% VO2max, the breakdown of muscle triglycerides did not increase. American scholars observed the results of aerobic exercise training for 3000 obese people, the average weight reduction of 30 kg during 5.5 years, 81% of the subjects physical activity (walking, weight lifting, cycling, jogging, climbing ladders, etc.) increased, and the energy expenditure of men and women were 2445 kcal/week and 3298 kcal/week respectively. At an exercise intensity equal to 40% of VO2max, fat oxidation provides 60% of the required energy to the muscles; the above ratio can reach 70% when continuous exercise reaches 120 min.
Because of the inconvenience of measuring VO2max, it is customary to use heart rate as the reference index of exercise intensity. In order to obtain the ideal exercise effect, while taking into account the safety, fatty liver exercise therapy should be achieved when the heart rate is called the target heart rate, can be easily calculated using the formula: target heart rate = 170 – age, and according to individual circumstances appropriate increase or decrease (up and down 10% range). If the patient’s age is 20 years old, the heart rate should reach 150 beats/min during exercise, which can be adjusted in 135-165 beats/min according to the patient’s physical quality.
3.Exercise time
Exercise time refers to the duration of each exercise, is an important factor in the composition of the amount of exercise. Studies have found that, in general, the smaller the intensity of exercise, the longer the duration, the higher the percentage of the total energy metabolism of the body relying on fat oxidation for energy supply. Long time small and medium intensity of the exercise process, fat becomes the main energy material. Therefore, it is advisable to exercise for a longer period of time. In terms of exercise for the treatment of fatty liver, experts have reached a consensus: to eliminate excess fat, the exercise time must be 30 min, because before that it is sugar that is often consumed rather than fat.
In exercise therapy for fatty liver, exercise can be either continuous or intermittent.
Continuous exercise is 15-60min in addition to preparatory and finishing activities, usually 20-30min, which has the advantage of improving cardiovascular function more quickly. If the exercise intensity is low, the exercise time should be extended accordingly. The first week of exercise should be moderate intensity exercise 20-30min, and after two weeks gradually extended to 45min.
Intermittent exercise for alternating exercise and rest, the ratio of exercise and rest time is 1:1, rest time should not be too long, and the total time of exercise should be longer than the time of continuous exercise (at least not less than the prescribed duration of exercise).
Studies have shown that at low intensity exercise (25% VO2max), the total fat and sugar oxidation rates change very little 30 min after the start of exercise compared to 2 h later. However, during moderate intensity exercise (65% VO2max), fatty acid consumption and utilization of glucose increased with time. The above study shows that the timing of exercise and the intensity of exercise are equally important.
4.Frequency of exercise
Exercise frequency usually refers to the number of times of exercise per week. The effect of exercise is shown in the gradual accumulation of benign effects of each exercise on the human body, is a process from quantitative to qualitative change, so require regular exercise. Japan Aichi University Sports Medical Center research found that the intensity of exercise is 60% to 80% VO2max, each exercise 45 min, at least four times a week to achieve good results of exercise weight loss.
In exercise therapy for fatty liver, the frequency of exercise depends on the intensity of exercise and the duration of each exercise. It can be performed 3-7 times per week depending on the need and functional status. Daily exercise can produce a better training effect.
5. Rate of progression of exercise.
In 3 stages.
① The beginning phase (4-6 weeks): should include stretching gymnastics and low-intensity aerobic exercise, so that the body is adapted to exercise and less likely to cause injury and muscle soreness. The duration should last at least 10-15min, and then gradually increase.
②Improvement phase: The intensity of exercise increases more rapidly over 2-3 weeks to reach 60-80% of the maximum functional level.
③Maintenance phase (after about 8 months of exercise): cardiorespiratory function reaches a satisfactory level, requiring the exercise load to remain unchanged and maintain a healthy state, and interesting other activities should be added in addition to walking and jogging to avoid interruption of exercise.
6. Time of exercise implementation: 1 hour apart after dinner is preferred.
Exercise precautions.
1, must be carried out on the basis of strict dietary control; exercise combined with dietary control and lifestyle changes is the best way to treat fatty liver. Try to limit the total energy of the diet, not only the intake of fat, during weight loss carbohydrate, fat, protein intake weight ratio of about 4:1:1.
2, there are preparatory activities before exercise and relaxation exercises after exercise; to avoid monotony, you can change the type of exercise.
3, the principle of individualization. According to the patient’s physical condition, according to the ability to do. To follow the principle of gradual progress, a few obese people because of infrequent exercise, muscle and joint stiffness, cardiopulmonary load, the initial amount of exercise should be small, and then gradually increase; with liver function abnormalities, the initial amount of exercise should not be too large, should be reduced by 10-20% of the regular exercise, but the exercise time can be slightly extended.
4, to avoid the occurrence of hypoglycemia, it is best to exercise within 1-3 hours after meals; diabetic patients before exercise to properly adjust the amount of insulin or hypoglycemic drugs, or exercise can be prepared with a little cookie, etc.
5, regular measurement of body weight, muscle strength, monitoring blood glucose and blood lipids, etc. to evaluate the effectiveness of exercise therapy. In terms of consuming excess fat, it is generally considered appropriate to lose 1 kg per week, while the main component of weight loss during rapid weight loss is water rather than fat. Exercise should be consistent and persistent.
Contraindications to exercise therapy.
1, in the acute phase of the disease, the condition is very unstable people.
2, there is a clear presence of acute inflammation, such as a body temperature of more than 38°C and a significantly elevated white blood cell count.
3.Persons with obvious psychiatric symptoms who are uncooperative.
4, those who have a tendency to hemorrhage
5, those who have not been properly treated for motor organ injuries
6.Persons who are physically debilitated and have difficulty with training
7.Persons with obvious tendency of cancer to metastasize
7.Persons with severe pain, which is aggravated after exercise
8. Poor general condition, or organ function loss period, should also temporarily contraindicate exercise therapy.
Monitoring of exercise amount
1, the appropriate amount of exercise signs: after the end of exercise, the heart rate returns to the pre-exercise level within 5-10min. Happy spirit and good appetite for sleep after exercise. Even if there is fatigue, muscle pain, can be relieved by a short rest.
2, the sign of excessive exercise: exercise fatigue, after the end of exercise, the heart rate can not return to the pre-exercise level in more than 10-20min. And after exercise, poor spirit, loss of appetite, poor sleep, muscle aches and pains, still can not be relieved by a long rest.
3, the signs of insufficient exercise: no fever, sweating and other phenomena during exercise, no significant changes in heart rate.