What Is the Difference Between Being Overweight and Obese?

Overweight is the phenomenon that the object is subject to a limiting force, which can also be referred to as the elastic force (pull or support) greater than the object's gravity. When an object performs an upward acceleration motion or a downward deceleration motion, the object is in an overweight state, that is, no matter how the object moves, as long as it has an upward acceleration, the object is in an overweight state. Overweight is more common when launching spacecraft, and all spacecraft and their astronauts are overweight at the beginning of the accelerated acceleration phase.

Chinese name: overweight
Foreign name: overload, overweight, superheavy
Meaning: An object's limiting force is greater than its own gravity

Experiment: On a satellite or deep sea dive
influences: Physical discomfort, difficulty breathing, etc.
Protective measures: Do intensity training

Overweight formula

From Newton's second law: Nmg = ma

So N = m (g + a)> mg

According to Newton's third law, the pressure of the object on the support is> mg

Concluded: Accelerate upwards and decelerate downwards: acceleration direction upwards, resulting in overweight

Therefore, as long as the acceleration direction is upward, it is overweight, regardless of the speed direction.

Overweight experiment

Since the successful launch of satellites and spacecraft, people have often talked about overweight and weightlessness. When spacecraft such as artificial earth satellites, spacecraft, and space shuttles are accelerating, the people and objects in them are overweight, and the pressure on the objects below them is several times their own gravity. When the spacecraft enters orbit, The people and objects are completely weightless, and they will not have any pressure on the objects below them. Objects can float in spaceships, which is hard to imagine on earth!

In fact, as long as an object has a vertical upward acceleration relative to the earth, it will produce an overweight phenomenon; otherwise it will produce a weightless phenomenon. It should be noted that no matter the object is overweight or weightless, the gravity of the earth acting on the object always exists, and the size has not changed, but the pressure of the object on the support (or the pulling force on the suspension) has changed, and it looks like the object s Weight has increased or decreased. So how to use experimental methods to study the phenomenon of overweight and weightlessness? Now an overweight and weightlessness experimental device has been produced using the "ditch card plate" trousers of daily necessities as the main material, and the experimental results are very good!

1. Experimental materials: 1 piece of wooden board (1.5 × 10 × 100cm), 1 spring (stiffness coefficient is 100N / m), 2 wood twisted loops, 1 thick iron wire, 2 grooved card-type trouser belts, 4 wood screws , 1 pointer, 2 slotted iron pieces (as shown in Figure 1), 1 500g hook code, 1 small wooden wedge card, glue (good guys), rivets, etc.

2. Production Method

Overweight experiment (1) Draw equal tick marks on one side of the board!

(2) At the end of the board, use a wooden screw to secure the spring and its pointer!

(3) Fix the trousers card. Take two trousers cards, and fix the slotted iron pieces with holes on the upper surfaces of the two trousers cards with A and B glue (good guys) (as shown in Figure 2). !!

(4) Fix the trousers card with grooved iron piece on the wooden board with wooden screws (as shown in Figure 3), where the card direction of the upper trouser card is upward and the card direction of the lower trouser card is downward!

Overweight experiment

(5) Cut off the groove plate parts of the two groove plate-type trousers with scissors, make the groove cards in opposite directions, and then connect them firmly with rivets (as shown in Figure 4, Figure 3, and Figure 4)!

(6) Pass the two ends of the inverted groove card board through the two trouser card on the wooden board, and make the card edge on the trouser card with the inverted groove card match the card direction of the trouser card. .

(7) The upper part of the trousers board with the inverted groove card is fixed with the spring on the wooden board, and the lower part is fixed with the thick iron hook in the wooden screw ring. Such an overweight and weightless demonstration experimental device has been successfully manufactured. .

Overweight experiment The card control twist on the upper trousers card is locked with a small wooden wedge (as shown in Figure 6) (making the card ineffective).

Hang a hook code with a weight of 500g on the thick iron hook. At this time, the spring is pulled down and the pointer points to a certain scale.

Hold the wooden board with your hand to accelerate the lifting forcefully. At this time, the spring suddenly expands, and the trousers board with the reverse groove card moves down. After stopping, it is caught by the card in the trousers card below. You can observe that the pointer slides down again. At a certain scale, this shows that when the system accelerates and rises, the object's pulling force on the spring is greater than its own gravity, which results in an overweight phenomenon.

Overweight training

Overweight training is a self-limiting challenge for astronauts. This is a kind of space physiology training to cultivate astronauts' ability to resist loads. Head

Overweight-centrifuge The purpose is to make astronauts adapt to the overweight environment when the spacecraft launches and returns to reentry, enhance the astronaut's ability to resist overweight, train the astronauts' overweight endurance, and the ability to manipulate the spacecraft and communications under overweight environmental conditions.

The training method for overweight adaptive training mainly uses a centrifuge to simulate the overweight curve of the spacecraft during take-off and return, and performs chest-back confrontation action training and head-pelvic endurance maintenance training. During the high-speed rotation of the centrifuge, the astronaut's facial muscles began to deform and sag; when doing overweight training in the pelvic direction, blood flowed to the lower limbs, causing ischemia and dizziness; when doing chest-back overweight, the front chest and back were compressed by a few blocks Hundred pounds of huge stones cause rapid heartbeat and difficulty breathing ... Every training requires a lot of energy. The centrifuge at the China Astronaut Center, which is currently used for the training of Shenzhou VII astronauts, is the largest manned centrifuge in Asia. It has a rotating arm up to 8 meters in length, and an oval stainless steel closed pod is attached to the front end. It resembles a "flying saucer" in the playground, but its speed and swing angle are "flying saucer". Are incomparable. When the centrifuge rotates at a certain speed, it can simulate the continuous overweight state of the manned spacecraft when it rises and returns.

1 G is the ground standard gravity environment. The human body structure and the regulating functions of various systems have been quite adapted to this. The roller coaster at the playground is a game for the brave, but after a few laps, brave people will feel dazed, and even some people look pale, dizzy and vomiting. The roller coaster body is overloaded by about twice its own weight (2 G). Normal people can't bear it when they reach a load of 3 G on a centrifuge. Astronauts usually need to be overloaded to 8 to 9 times their own weight, which is 4 times stronger than a roller coaster. The duration is 40 to 50 seconds. , Ordinary people are unimaginable. During this training, the astronaut's facial muscles are deformed under the traction of powerful forces, tears flow out unconsciously, and breathing is extremely difficult.

During the high-speed rotation of 100 kilometers per hour, the astronauts must not only practice anti-load actions such as abs and abdominal breathing, but also answer questions at any time, interpret signals, and maintain agile judgment and response capabilities.

Overweight effect

During the launch and return of the spacecraft, due to acceleration, overweight occurred. G value is usually used to express it. in case

Overweight training A 50 kg person weighs 50 kg in a 1G environment, it becomes 100 kg in a 2G environment, and 150 kg in a 3G environment. An excessively high G value is harmful to the human body, and even fatal. The early rocket overweight value was 7-8G, and the new rocket has been reduced to no more than 5G. Due to the development of propulsion technology, the peak value of the space shuttle launch can be controlled at 3G level. The maximum re-entry overload for normal return is + 4Gx ~ + 5Gx. When the space shuttle reentered, the crew encountered an overweight effect in the + Gz direction, and the overload was not greater than 3G. In the launch section, this overweight effect has little effect on the human body and can be tolerated by astronauts. However, after a period of weightlessness flight, the astronaut's ability to regulate the cardiopulmonary system decreased, and overweight in spaceflight still had some effects on the human body.

1. The overweight of 7G to 8G generated by the early rocket launches has been reduced to less than 5G for newer rockets. Due to the development of propulsion technology, the space shuttle can be controlled at the 3G level during launch, regardless of the launch section or the return section. Astronauts are basically subject to + Gx overweight, the direction of gravity, the value of the value, the duration, The rate of change and the duration of repetitive action, as well as the physical condition of the astronaut, are the main factors in determining whether they can tolerate. Under the effect of longitudinal overweight (+ GZ), due to the effect of hydrostatic pressure, the blood distribution of the whole body is changed. The blood is retained in the lower parts of the human body such as the lower limbs, which reduces the amount of returning blood. Causes head blood supply disorders, light causes visual changes, and serious causes loss of consciousness.

With lateral overweight (+ Gx), astronauts will experience difficulty breathing and chest pain when visual and brain dysfunction have not yet occurred. Some can also occur cardiac rhythm disorders and reduced oxygen saturation. Relevant research proves that normal people can generally tolerate 10 ~ 12G, and after training, appropriate protective measures may also tolerate higher G values. In the case of -Gx, severe symptoms such as severe headache, conjunctival congestion, epistaxis, and redness can occur at 3 ~ 4G, which is generally the upper limit of safety. Above -4.5Gz for several seconds, it can cause mental disorders or even loss of consciousness.

Lateral overweight (± Gy) generally occurs when the spacecraft has a composite flight such as yaw, roll, pitch, etc., and the G value action time in actual flight is not long. According to research reports, tracking movement can be affected at ± 1G and 2G, and severe internal organ tearing injuries can be caused at ± 5Gy.

2. Stapp used a rocket tackle to test that black bears and orangutans were decelerated and overloaded by 83Gx. It was found that the lungs, heart, liver, and spleen were severely damaged, spine fractures, organ ruptures caused major bleeding, and fatal injuries occurred.

3 During normal re-entry, the overload is less about 4G ~ 5G, and the duration is about tens of seconds to several minutes, so it belongs to the impact of continuous overweight on the human body.

4 According to the rocket and pulley test, under the condition that the human body seat belt is well fixed, it can withstand 35-g back-to-thoracic deceleration overload, a growth rate of 100 G / s, and an action time of 0.15 to 0.35 s. The subject may have blood pressure drop and pale. , Shock symptoms such as cold sweat, no tissue damage.

5. During the landing impact of the human-cabin system, the impact force is transmitted to the person through the seat, and there is no self-buffering effect of the human body. In addition, when the landing impact of the human-cabin system is more than 30ms, the landing impact overload of the human body is greater than the impact overload input by the seat. Due to the dynamic overshoot of the human body, people sitting in the cabin and parachute landing different.

6. When the human body is landing in an impact, the impact overload is transmitted to the seat through the cockpit and finally to the person, similar to the hip landing. The main reactions are pain, visceral injury and bone injury in severe cases.

7. In dogs with high G-values (30Gz ~ 100Gx, 10 ~ 100ms) in sitting impact tests, it was found that congestion, bleeding, edema, and lacerations of the liver, lungs, and spleen were caused by congestion, bleeding, and edema of organs such as the brain, lungs, liver, and heart. Blood in the chest and abdomen. Kazarian reported that liver, lung, and heart injuries were observed when monkeys were subjected to 25G ~ 900G 2-22ms sitting shock. Spinal ligament lacerations, spinal fractures, etc.

8. Domestic dogs in supine (+ Gx) fall impact experiments found that under the impact of 10Gx ~ 60Gx30 ~ 100ms, lung and heart injuries were the main cause, and a few were accompanied by bleeding from liver, spleen, kidney and other organs. With the increase of G value, the damage was aggravated, and in severe cases, fractures of the ribs caused by ruptured organs occurred.

9. The causes of human-cabin system landing impact injuries are mainly due to the direct action of the impact force exceeding the tissue strength, and due to the organ displacement, deformation, pulling and collision with each other during the impact.

10 The landing impact test of the human-cabin system showed that the landing injury in the vertical position was more serious, and the supine position was lighter. The forward tilt position easily caused heart damage, and the right tilt position easily caused liver damage. Regarding the landing of the human-cabin system, the endurance of the human body to the landing impact is currently not clearly defined.

11. Based on the subject's pain response at the time of impact and the changes in a large number of physiological indicators, it was initially proposed that the human body was subjected to peak 23G, 30ms, peak 19G, 50ms, peak 16G, 80ms, peak 14G, 100ms, which can be used as physiological tolerance levels; when the peak Greater than 23G, 50ms may cause spinal injury.

12. The landing speed of a manned spacecraft is generally no more than 6m / s on land and no more than 10m / s on water.

Overweight protection measures

Overweight Overview

In order to ensure the safety of astronauts during the ascent and return of the spacecraft, to counteract the effect of lateral overweight (+ Gx) on the human body, and to protect the space from overweight,

overweight The most effective method is to try to reduce the overload of the launch and return sections of the spacecraft from the project, and try to avoid the occurrence of overload of the emergency control provider. In medical protection, it is generally to minimize the impact of overweight on the human body and improve the body's tolerance to overweight. Specifically, it is achieved through the selection, training of astronauts' super endurance, and the comprehensive application of various protective measures. Aerospace medicine believes that all measures and technologies that can improve the body's sustained acceleration endurance can increase the acceleration effect encountered by the body on the return section of the aircraft and extend the duration of space flight.

Overweight ideal seat and fit cushion

As mentioned above, due to the characteristics of the physiological structure of the human body, in the case of overweight action in different directions, the endurance from + Gx overweight action is the highest. Therefore, it is more advantageous for the astronaut to take a supine posture during the launch and return stages of the manned spacecraft. . As far back as the 1930s and 1950s, many exploratory studies have been conducted on the effects of different supine dorsal angles (ie, effective physiological dorsal angles in flight) on body endurance. The results show that compared with the sitting position, the overweight endurance is slightly improved when tilted back 45 °, 2.5G at 77 °, and 3.5G at 85 °. Later, a lot of research was conducted around the need for high overweight protection. As the back angle increases, the overweight endurance of people gradually increases. The reason why increasing the back tilt angle can improve the overweight endurance of people is that when the back angle is increased, the vertical distance between the eyes and the heart decreases with the increase of the back angle, thereby reducing the hydrostatic pressure effect. However, when the back angle is too large, people are prone to breathing difficulties and chest pain, as well as frequent premature beats. Therefore, choosing an effective physiological dorsal angle is of great significance for improving the overweight endurance and the design of the manned spacecraft. Through research and observation, scientists have proposed the best and reasonable reclining chair position, that is, the back angle is 75 °, the position of the legs is about 100 ° with the torso, the knees are slightly higher than the head, and the lower legs are flat.

Overweight use of anti-wear

Anti-load clothing is a physical protective measure: it can prevent blood flow to the lower limbs due to inertial force and hydrostatic pressure gradient during overweight action, increase venous return, increase cardiac output, and improve head fluid supply. Increase your endurance to overweight. Anti-loading is particularly effective in prolonged acceleration of the + Gz component. Anti-loading clothing is usually divided into two types: cystic anti-loading clothing with 5 airbags, of which only 1 abdominal sac, 2 thigh sac and 2 calf sac. Begin to inflate the capsule at 1.5 ~ 2.0Gz, this kind of anti-wear can improve the endurance of about 2G. The basic structure of the tubular anti-wear suit is tights made of a material with a small stretch coefficient. There are two inflatable side tubes on the sides of the pants. When this tube is inflated, the pressure guiding belt pulls the clothing side tightly. Body compression, such anti-loading clothing is more complicated. Russia and the United States have begun to use a non-capsule anti-loading suit to prevent astronauts from syncope when the G value of the reentry segment increases.

Overweight positive compression breathing

Positive pressure breathing can be applied simultaneously with breathing pure oxygen. The principle of its protective effect is that the physical counter pressure is applied to the pulmonary blood vessels, which reduces the blood stasis in the pulmonary circulation and increases the aortic arch pressure in the system circulation circuit. Compared with other protective breathing technologies, this method reduces the work of external breathing, thereby reducing energy consumption, increasing blood pressure in the cerebral blood vessels, and reducing visual disturbances. Some studies have shown that applying this method during acceleration can also reduce the induction of cardiac rhythm disorders. The best lung compression method is 2 ~ 3mmHg / G, it can extend the overweight tolerance time by 67%, and the protective effect is 1.1 ± 0.2G (+ Gz).

Overweight physiological protection method

Some physiological protection methods can significantly improve people's overweight endurance. Experienced astronauts have used the following two methods when performing flight missions or when the spacecraft reenters and returns: the first is to continuously tighten the abdominal and leg muscles, and the second is tonic breathing technology. The application of these methods can improve the overweight endurance of 1 ~ 3G. Its protective effect comes from the compression of the deep blood vessels in the legs, the abdominal cavity and the pulmonary circulation, reducing the accumulation of blood in lower parts of the body.

Overweight physical exercise

Ground sports training can effectively enhance the physical fitness of the human body. For example, short-distance speed running and speed swimming can enhance the cardiovascular emergency regulation ability, weightlifting and other training can enhance the tension of the leg muscles and abdominal muscles. These special sports training can improve the astronaut's overweight endurance. At this time, the purpose of physical training is to improve the breathing and circulation regulation function under low dynamic conditions, increase the static endurance of abdominal muscles, and develop anti-gravity technology. The purpose of training is to improve people's overweight endurance and adaptability to space overweight environment . -Generally, we can start from two aspects, one is to improve physical fitness, and the other is to skillfully apply protective facilities and methods to improve the protective effect. So that each astronaut is in the best condition.

Overweight centrifuge training

Centrifuge training is one of the most effective methods to improve overweight endurance, and it has been widely used in space training in countries around the world. Centrifuge training can increase + G endurance by about 1.6 ~ 5.8G.

Overweight comprehensive anti-load measures

In manned space flight, comprehensive protective and preventive measures are often used. At present, the use of physiological protection technology and anti-load clothing in flight has become routine. In long-term space flight, after the astronauts have adapted to the weightless environment, they encounter the acceleration effect of the re-entry segment, and they need to adopt comprehensive protective devices and technologies. According to reports, the combined application of the seat back tilt and pressurized breathing of the shaped cushion can increase the overweight endurance to + 26.5Gx (1G / s). Therefore, people pay more attention to the comprehensive application of protective measures during medium and long-term flight. These comprehensive countermeasures allow astronauts to maintain a high level of ergonomics in weightless environments and during exposure to overweight during reentry.

Selection of overweight and endurance

There is a large individual difference in the tolerance of the human body to the effects of overweight. Some people have a significant heart rate slowdown around + 6Cx, while some people have no adverse reactions at + 12Gx fashion. In order to enable astronauts to withstand the overweight effects of the launch and return sections, people have attached great importance to the selection of astronauts' overweight endurance since the early days of manned spaceflight. Selection for overweight endurance is usually performed on a manned centrifuge. Astronaut overweight endurance check generally includes + Gz endurance check and + Gx endurance check. During the test, the subject's tolerance G value, subjective sensation, and various physiological responses including vision, breathing, cardiovascular system, vestibule, and blood oxygen saturation were evaluated. Generally, overweight endurance is divided into three categories: "good, medium, and poor". The "good" is selected, the "medium" is qualified, and the "poor" is unqualified. The purpose of training is to improve human overweight endurance and adaptability to the space overweight environment. -Generally, we can start from two aspects, one is to improve physical fitness; the other is to skillfully apply protective facilities and methods to improve the protective effect.

Overweight fitness training

The overburden of the transmitting and returning sections is sudden and high-intensity, which requires the body's heart to have a strong compensation reserve, and the cardiovascular system has rapid response and stress regulation capabilities. This ability is directly related to sympathetic tension activity. For this reason, astronauts should be allowed to appropriately increase short-distance speed training, short-distance speed swimming, and special physical training such as weightlifting and weightlifting on the premise of insisting on daily physical training. Short-distance sprinting and short-distance sprinting help to enhance the rapid compensatory response of the cardiovascular system. Weightlifting and weightlifting can enhance the sympathetic tension of the body, and can reduce the capillaries in skeletal muscle, which has a significant effect on improving overweight endurance.

Overweight and hypoxic adaptive training

In the training of astronauts, it is an effective and non-specific method to improve acceleration endurance by properly interspersing adaptive training to hypoxia. It has been reported that the survival rate of mice, rats, and Dutch pigs that were hypoxic-adapted before exposure to acceleration increased by 15% to 20% compared to the control group without hypoxic-adaptation training. Adaptive training with hypoxia plus exercise is more effective. When people are exposed to high mountains, their + Gx endurance is 2.4 ± 0.2G higher than that of the control group. The protective effect of hypoxic adaptation is to improve the re-adaptation ability of the cardiovascular system, that is, to increase the tolerance of nerve cells to hypoxia and decreased blood oxygen saturation caused by circulatory disturbances.

Overweight Altitude Training

The density of moderate plateau air is only 77% of the altitude plane. The oxygen content is only about 3/4 of that in the plain area, and the partial pressure of oxygen is greater than 20-25% in the plain area. When athletes are trained in such an environment, due to stress during the "adjustment period", breathing frequency and heart rate increase, Part of the oxygen dissolved in the blood vessels is not easily absorbed by the body due to the effect of low air pressure, which increases the volume of the blood vessels, expands the blood vessels, thickens the walls of the blood vessels, thickens the blood vessels, and increases the amount of blood passing through, thus better training the athlete's heart The vascular system increases the maximum oxygen uptake and hemoglobin concentration, and enhances the ability to tolerate lactic acid. Produced plateau domestication (service). Upon returning to the plain, the adaptive conditions were lost. Athletes will generate stress under new conditions. Domestication at night-undressing. Perform altitude training before the competition. The effect on the improvement of athletic performance is significant. Each training is about three weeks. Due to the difficulty of finding high altitude training locations, the expenditure is large.

PC Overweight PC machine training

It is often said that micro domestication, the principle and analogy of altitude training.

Overweight, overweight

Overweight and obesity are defined as abnormal or excessive fat accumulation that can harm health. Body mass index (BMI) is a simple index of weight / height.

Overweight For the classification of overweight and obesity in the adult population and individuals. It is defined as the weight in kilograms divided by the square of height in meters (kg / m2). Body mass index is the most useful measure of overweight and obesity at a population level because it is the same for men, women, and adults of all ages. However, it should be considered as a rough guide as it may not indicate the same degree of obesity in different individuals.

The World Health Organization defines "overweight" as having a body mass index equal to or greater than 25, and "obesity" as defining a body mass index equal to or greater than 30. These trade-off points provide a benchmark for individual assessments, but there is evidence that the risk of chronic disease in the population has gradually increased since the body mass index 21.

The new WHO Child Growth Standards, released in April 2006, include BMI tables for infants and young children under 5 years of age. However, measuring overweight and obesity in children between 5 and 14 years of age is challenging because there is no worldwide definition of childhood obesity standards. WHO is currently developing an international growth reference for school-age children and adolescents.

The root cause of obesity and overweight is an energy imbalance between the calories consumed and the calories consumed. The rise in global overweight and obesity can be attributed to several factors, including: changes in global diets, increased intake of high-fat, high-sugar, but high-energy foods lacking vitamins, minerals, and other micronutrients; and many forms of work The need for sedentary nature, ever-changing modes of transportation, and increasing urbanization have led to a reduction in physical activity.

What are the common health consequences of being overweight and obese? Being overweight and obese can have serious health consequences. As the body mass index rises, the risk gradually increases. Increased body mass index is an important high-risk factor for chronic diseases such as: Cardiovascular disease (mostly heart disease and stroke)? This is already the number one cause of death in the world, causing 17 million deaths each year. Diabetes? Has quickly become a global epidemic. According to WHO forecasts, the number of diabetes deaths will rise by more than 50% worldwide over the next 10 years.