Impact of mild dehydration on wellness and on exercise performance

Impact of mild dehydration on wellness and on exercise performance

Top of pageAbstractChronic mild dehydration is a common condition in some population groups, including especially the elderly and those who participate in physical activity in warm environments. Hypohydration is recognised as a precipitating factor in a number of acute medical conditions in the elderly, and there may be an association, although not necessarily a causal one, between a low habitual fluid intake and some cancers, cardiovascular disease and diabetes. There is some evidence of impairments of cognitive function at moderate levels of hypohydration, but even short periods of fluid restriction, leading to a loss of body mass of 1 lead to reductions in the subjective perception of alertness and ability to concentrate and to increases in self reported tiredness and headache. For a healthy lean young male with a body mass of 70 kg, total body water will be about 42 l. The turnover rate of water exceeds that of most other body components. For the sedentary individual living in a temperate climate, daily water turnover is about 2 l. In other words, about 5 of the total body water content is renewed every day Lentner, 1981. In spite of its abundance, however, there is a need to maintain the body water content within narrow limits, and the body is much less able to cope with restriction of water intake than with restriction of food intake. A few days of total fasting has little impact on health and functional capacity, provided fluids are allowed, and even longer periods of abstinence from food are well tolerated. In contrast, except in exceptional circumstances cessation of water intake results in serious debilitation after times ranging from only an hour or two to a few days at most.

The performance of prolonged exercise, particularly in warm environments, can result in a substantial loss of body water, with the potential for adverse effects on performance capacity, and an increased risk of heat related illness. An athlete training hard in a spell of warm weather, or a person with a heavy manual job working in the same conditions, may lose several litres of sweat in a single day: in extreme conditions of work in the heat, daily sweat losses may reach 10 l or even more. This amounts to about one quarter of the total body water content for the average man, and about one third for the average woman. In spite of this high daily rate of exchange, a water deficit of only a few percent will impair physical performance: a slightly larger loss will bring symptoms of tiredness, headache and general malaise. If the loss of water reaches 10 of body mass, about 20 of total body water, death is the likely outcome. It may not be possible to prevent loss of substantial volumes of sweat in either physically demanding occupational tasks or in sporting competition, so there must be an emphasis on fluid replacement strategies to protect health and to maintain performance capacity.

Top of pageDaily water turnoverWater is lost from the body in varying amounts via a number of different routes: the main avenues of water loss are urine about 1400 ml, faeces 200 ml, insensible losses from the lungs 400 ml and loss via the skin 500 ml. The total daily water loss is therefore about 2500 ml, but this varies greatly between individuals and depends on the environmental conditions. When the air is dry, water loss from the skin and lungs is increased because of the increased vapour pressure gradient, and more water is also lost by these routes in hot weather. The amount lost in the urine depends very much on the volume of fluid consumed and on the total losses by other routes. It also depends on the solute content of the diet, and high intakes of salt sodium chloride or protein will increase the daily fluid requirement because of the limited capacity of the kidneys to concentrate the urine. If water intake is restricted, the kidneys will conserve water by producing a more concentrated urine: the concentrating capacity varies between individuals, but the maximum urine osmolality is typically about 900 mosm/kg Lentner, 1981. Equally, the body cannot store excess water, so the kidneys get rid of any temporary excess by producing a large volume of dilute urine. Daily fluid intake in man is usually in excess of perceived need and water balance is maintained by urinary losses Engell Hirsch, 1991.

For individuals at rest in temperate environmental conditions, body temperature is maintained at a comfortable level primarily by behavioural mechanisms: adjusting the environmental conditions or the amount of clothing worn are effective at increasing or reducing heat loss. When the environmental temperature is high, physical transfer of heat from the body is not possible, and evaporation of sweat from the skin is the bodys only way of getting rid of excess heat. All the metabolic reactions in the body result in heat production, but at rest the body produces heat only slowly: about 60 W for an average 70 kg individual. In exercise, the rate of heat production rises: for a 70 kg person running at 15 km/h the rate of metabolic heat production will increase to about 1 kW, and body temperature would rise rapidly if there was not a corresponding increase in the rate of heat loss. Sweating is a very effective way of preventing body temperature from rising too far, but causes the loss of water and electrolytes salts from the body. Our runner would need to produce about 1.5 l of sweat per hour to balance the rate of heat production, and trained athletes can sustain this running speed for several hours with little rise in core temperature. Even a loss of as little as 1 l of sweat will increase the sense of fatigue and impair performance, so replacement of fluid losses during such forms of exercise is clearly a priority. A table of sweat losses in various sports situations has been compiled by Rehrer Burke, 1996.

Maintenance of body temperature at rest and during exerciseIn all but the most extreme conditions, body temperature is maintained within about 2 of the normal resting level of 37 This, of course, applies to the temperature of deep body structures, including especially the brain, rather than to skin temperature. The temperature of bare skin follows the environmental temperature and is not closely regulated. There appears to be a critical body temperature above which humans and other mammals will not continue to exercise voluntarily. A consistent finding in the published literature is that voluntary fatigue occurs at a core temperature of about 40 Gisolfi Copping, 1974; Nielsen et al, 1993, 1997. An inability of the central temperature control mechanism, or of the effector mechanisms that respond to input from the hypothalamus, to compensate for orthostatic simultaneously, metabolic and thermoregulatory demands may result in heat syncope, characterised by extreme peripheral vasodilation and a fall in arterial blood pressure Werner, 1993. This condition is not very harmful compared to heat stroke during high heat stress, where the requirement for thermoregulation is subordinated to cardiovascular and metabolic demands Werner, 1993. There are thermal limits that the brain tolerates, and when these limits are reached a host of physiological reactions occur that may be aimed at reducing the rate of brain heating, but often result in heat stroke. Important among these is the cessation of physical activity that results in a marked reduction in the rate of metabolic heat production.

Nielsen et al 1993, 1997 have speculated that at a critical core temperature about 40 in humans there may be a negative effect on the brains motor control centres. Such effects are consistent with the loss of motor coordination, reduction in motor drive and increased perception of effort that typically occur in the later stages of prolonged exercise in the heat. Evidence for a direct effect of elevated core hypothalamic temperature on impaired neuromuscular function comes from studies that show increased exercise time to fatigue when individuals exercise in cool conditions Galloway Maughan, 1997; Parkin et al, 1999. Performance of endurance exercise is also improved when subjects are actively cooled during the period of exercise MacDougall et al, 1974 or have been cooled prior to starting exercise Lee Haymes, 1995.

Top of pageHydration status and wellnessDehydration is associated with a number of negative effects on health and well being, although the evidence that mild dehydration is harmful is not supported by any strong evidence. There is general agreement among clinicians that chronic mild fluid restriction will compromise health, but there is limited solid evidence to substantiate this clinical impression. Severe dehydration is clearly detrimental to health, and is associated with compromised cardiovascular function, renal impairment, weakness and lassitude, and a number of diffuse symptoms, including headache, nausea and general malaise. Specific health risks of a chronically inadequate fluid intake are difficult to define, for a number of reasons, including the diffuse nature of the symptoms, the difficulty in obtaining reliable estimates of fluid intake, and the absence of any agreed marker of hydration status. There does seem to be some evidence of a link between habitual fluid intake and cancers of the bladder Michaud et al, 1999, and colon Shannon et al, 1996. Links with other disease states, including diabetes and cardiovascular disease have also been postulated, but the evidence is somewhat tenuous Burge et al, 2001; Chan et al, 2002. It is also the case that individuals with a high fluid intake may be chronically hypohydrated if they also have a high water requirement, so water turnover may not be a good index of tissue hydration status Shirreffs Maughan, 1998.

There are undoubtedly some negative subjective symptoms associated with even modest levels of dehydration. Self ratings of alertness and ability to concentrate decline progressively when fluid intake is restricted to induce body mass deficits of even as little as 1 At the same time, ratings of tiredness and headache increase Figure 1. There are also some indications in the published literature that cognitive function, as assessed by decision making and reaction time tests, is also impaired at relatively low levels of dehydration Gopinathan et al, 1988. This may be important when decisions have to be made or where judgement and skill are involved; driving a motor car is a good example of such a task. In all, 15 healthy adults participated in two trials: in one trial, fluid intake was restricted for 37 h and normal drinking was allowed in the other trial. Body mass loss was 2.68% in the fluid restriction trial and 0.58% in the control trial Shirreffs, unpublished data.

Full figure and legend 32K

Populations at particular risk of dehydration and its sequelae include the very young and the elderly. Limited data are available on the prevalence of hypohydration, but there is some evidence to suggest that this may be relatively common among some sections of the elderly population Leaf, 1984. Although the evidence that dehydration has a significant negative effect on brain function in healthy young individuals is limited, it is quite possible that mild to moderate dehydration may exacerbate any pre existing impairment of cognitive function in the elderly, and dehydration is recognised as one of the factors that may precipitate acute confusion in the elderly Mentes et al, 1998. Again, clinical experience suggests that the confused elderly patient admitted to care is commonly in a state of fluid deficit. This state may occur because of a reduced thirst response to a fluid deficit in the elderly, a reduction in renal function and an alteration in the secretion of hormones involved in water and electrolyte homeostasis Miller, 1998. Elderly individuals suffering from chronic physical and/or mental impairment are likely to have low levels of daily water turnover and to be at increased risk of hypohydration Phillimore et al, 1998.

In spite of great improvements in sanitation and in the availability of rehydration solutions, dehydration resulting from infectious diarrhoeal disease remains one of the largest single causes of death among young children, being responsible for about 1.5 million deaths annually around the world WHO, 2002. Healthy children may also be at risk of dehydration if there is a sudden increase in water loss for any reason, and physically active children will be at particular risk during periods of warm weather. The large surface area:volume ratio of children relative to adults the average 6 year old child has a surface:volume ratio about 50% greater than that of the average adult means that they gain more heat through the skin when the environmental temperature exceeds skin temperature Bar Or, 1989. In this situation, an increased rate of evaporative cooling is essential to prevent a catastrophic rise in body temperature. This is achieved at the expense of an increased loss of water from the body, but children may be less aware of the need for increased drinking and may have a relatively insensitive thirst mechanism and may need encouragement to drink when losses are high.

Top of pageEffects of dehydration on exercise performanceAlthough the physiological consequences of dehydration due to the sweat loss that occurs during exercise have been the focus of much attention, there has been relatively little scientific interest in the effects of a fluid deficit incurred prior to exercise. Both of these situations, however, are common in sport. Individuals who begin exercise with a fluid deficit will not perform as well as they will when fully hydrated. This has been shown to be true whether the fluid deficit is incurred by prolonged exercise in a warm environment, by passive heat exposure or by diuretic treatment Nielsen et al, 1981; Armstrong et al, 1985. An impaired performance is observed whether the exercise lasts a few minutes, or whether it is more prolonged, although muscular strength appears to be relatively unaffected, and tasks with a large aerobic component are affected to a greater extent than those that rely primarily on anaerobic metabolism Sawka et al, 1990.

There seems to be relatively little effect of mild dehydration on muscle strength Table 1. There are, however, some difficulties in the interpretation of these studies as the methods used to induce dehydration usually include either heat exposure of exercise, both of which will induce elevations of muscle temperature which will in itself affect the contractile properties of the muscles. Where dehydration has been induced over a longer period by restriction of fluid intake, there is also commonly a reduced food intake, leading to changes in muscle glycogen content and in the acid status of the muscle.

In exercise tests lasting more than a few minutes, reductions in performance are apparent at modest levels of body water loss amounting to 1 of the pre exercise body mass Armstrong et al, 1985. For the average young male most of the subjects in these studies have been male, but the responses of female subjects do not appear to be different, body water accounts for about 60% of total body mass, so these levels of hypohydration amount to about 2 of total body water. It was reported by Adolph et al 1947 that subjects do not report a sensation of thirst until they have incurred a water deficit of about 2% of body mass. This suggests that athletes living and training in the heat may not be aware that they have become dehydrated to a level sufficient to affect performance adversely. Athletes living and training in warm environments, especially those used to living in cool climates, will often fail to consume sufficient fluid to maintain hydration status and may need encouragement to do so Shirreffs Maughan, 1998.

Fluid losses due to sweating are distributed in varying proportions among the various body compartments: plasma, extracellular water and intracellular water. The decrease in plasma volume that accompanies dehydration may be of particular importance in influencing work capacity. Blood flow to the muscles must be maintained at a high level to supply oxygen and substrates, but a high blood flow to the skin is also necessary to convect heat from the active muscles and the body core to the body surface where it can be dissipated Nadel, 1989. When the ambient temperature is high and blood volume has been decreased by sweat loss during prolonged exercise, there may be difficulty in meeting the requirement for a high blood flow to both these tissues. In this situation, skin blood flow is likely to be compromised, allowing central venous pressure and muscle blood flow to be maintained but reducing heat loss and causing body temperature to rise Rowell, 1986. More recent data, however, suggest that dehydration may cause a reduction in the blood flow to exercising muscles as well as to the skin Gonzalez Alonso et al, 1998. It may be that a falling cardiac output and an imminent failure to maintain blood pressure is one of the signals responsible for exhaustion when dehydration occurs during prolonged exercise.

These factors have been investigated by Coyle and his co workers in a series of elegant studies; their results clearly demonstrate that rise in core temperature and heart rate and the fall in cardiac stroke volume during prolonged exercise are graded according to the level of hypohydration achieved Montain Coyle, 1992a. They also showed that the ingestion of fluid during exercise increases skin blood flow, and therefore thermoregulatory capacity, independent of increases in the circulating blood volume Montain Coyle, 1992b. Plasma volume expansion using dextran/saline infusion was less effective in preventing a rise in core temperature than was the ingestion of sufficient volumes of a carbohydrate electrolyte drink to maintain plasma volume at a similar level Montain Coyle, 1992b. This raises some questions about the mechanism of action of fluid replacement during exercise, but these studies confirm the importance of the ingestion of drink of a suitable composition and in sufficient volume during prolonged exercise in a warm environment.

Sports shoes synthetic materials are widely used

sports shoes synthetic materials are widely usedDassler Brothers broke up in 1948, his brother set up a sub-Astoria Addas company, which is later Adidas-adidas predecessor; Dassler same at the other end of the start-up of the business is booming town of Puma-Puma the company. Adidas was founded the worlds first sneaker Expo, the most complete collection since 1924 athletics shoes; while Puma is saved the company early running shoes and sports shoes for many years the research results obtained patent. Two brothers war in the Olympics, every four years to achieve the most intense level of competition, the two companies are well-known athletes free design special shoes, which greatly promoted the development of sports shoes. Later, sports, entertainment and sports, more and more began to appear some special shoes. At that time sneaker features a dedicated athlete can only wear in football, rugby, cricket sports leather sole shoes with Oxford shoes similar to a rubber sole also called Oxford bottom. Is often at the bottom of the installation of non-slip soles or spikes protruding bolt. Most representative of the Olympic Games began in 776 BC in Olympia, Greece, the village, the project is mainly running, and later increased sport fencing, wrestling, archery, boxing, etc. For best results, athletes gradually from running without shoes to wear shoes. Running shoes and thus gradually developed. In 1968, invented the whole piece is inserted in the upcoming modification to the bottom of the Japanese bathroom slippers sneakers. That year also appeared to be designed to lower the height of the heel sneakers mouth lines are not filling the shoes I like foam pads to increase its comfort. But in between the upper and the insert inside the main root after Hong Kong Po, became one of sport shoes uppers components commonly used later. The men are usually the bottom half with the heel pad or pads. Women with full coverage bottom pad. Insole insole has kept clean, covering the bottom of the rugged, in order to improve the role of Jiaogan. Sports shoes or sneakers is a no with flat shoes. It does not guarantee evenly distributed throughout the body center of gravity of the foot, not the body muscles, ligaments, bones and spine to maintain a normal position and work status. After the teenagers wear athletic shoes or sneakers gravity changes in the body, the feet appear uneven distribution of forces will affect the footwork. Classic sneakers originated in ancient messenger running long distances. At that time, the messenger are in the form to send commands to run on the battlefield. In order to be able to quickly pick running messenger, was born of the ancient Games. Later in turn cut a fresh animal skin wrapped the foot, and wrapped in animal skin will become increasingly hard, even mill feet, cut feet. Hand tools they use human bones made ??of stone or animal skin treated more softer, or switch to a more flexible material. They also found in the soles of the feet will be strapped bark, animal skins and even other substances, made with the sole shape substantially similar to their bondage again scattered and not easily punctured.

How To Make a Hope Chest

How To Make a Hope Chest<br /><br />A hope chest is something that is used by women before they start their married life. This can also be called a dowry chest or glory box. This chest will hold the items that the bride will bring with her when she gets married and leaves her familys house. The common contents of a hope chest include items of clothing, jewelry, linens, dishware and other important items for the bride.<br /><br />Many years ago, the hope chest was passed on by women from generation to generation. Nowadays, women hardly ever use a hope chest but some families still carry on with the tradition. If you do not have a hope chest to hand down to your daughter, maybe its time that you make one so that you can take part in this meaningful tradition<br /><br />Choose the wood. The first thing that you will have to determine is what type of wood you are going to use for the hope chest. The most common wood used for this is the cedar. This is because cedar is not only durable, but it also gives off a fragrant smell that also acts as moth repellent. You can also choose other types of wood, such as cherry wood or pine wood.<br /><br />Size of the chest. There is no standard size for a hope chest. You can make it as big or as small as you want. Take into consideration the number of items that you are going to put inside it. On average, a hope chest has a length of four feet, a width of two feet and a depth of two feet.<br /><br />Creating the chest. When you already have the proportions of wood needed for the hope chest, you can use wood glue to put the pieces together and form a chest. The next part is designing the chest according to your taste. This is not necessary but it will make the hope chest more attractive. Most hope chests from long ago were carved with intricate designs and patterns. However, if you want a more modern feel to your hope chest, you can always paint on the wood.<br /><br />Pass down the chest. After using the chest, you can start a new tradition and pass it down to your daughter. If you do not have a daughter, you can give it to a niece. Explain the symbolism and importance of the hope box so that she can carry on the tradition.<br /><br />These are the steps on how you can create your own hope chest. You can put a lot of items inside the chest. You can put your wedding gown inside or some jewelry that you would like to pass down to your daughter. You can even put old letters or photos of your ancestors so that the younger generation of your family can get to know where they came from. Passing down this hope chest will surely be an exciting thing for you to do.

How To Identify a Real Diamond

How To Identify a Real Diamond<br /><br />A diamond is one of the most valuable gemstones known today. It has been used since the ancient times by shamans, leaders of tribes, royalties, dignitaries, dictators, revolutionary individuals, wealthy citizens and the like. Its earliest documented records were found in the Sanskrit texts in India. Due to its cunning features and valuableness, this elegant gemstone has spread all over the world starting from India to China, Ancient Rome, South Africa and Brazil. blood diamond in Africa. As the twentieth century unfolded, chemists and scientists started to create a man made diamond wherein it was chemically produced. This synthetic diamond is worth much lower than the naturally made ones but it is still valuable and can stand the test of time. Identifying a real diamond can be a bit tricky especially when you are new to this kind of thing. Read on to learn more.<br /><br />A refracted image. Get a newspaper, a magazine or a book. Put your diamond on the surface and try to read through it, like a magnifying glass. If you can actually see the letters quite clearly that you can read through the stone, then your diamond is not real. A true diamond dramatically refracts the light so much that you will not be able to see through an image or text at all.<br /><br />Breathe through it. Due to its natural composition, it is a superb conductor of heat. Try breathing through it and check if condensation appears. If it does, then you have a fake diamond.<br /><br />Sparkly or not? Put your diamond up against the light. Carefully scrutinize it by checking how it sparkles in different angles. A fake diamond should only sparkle at a certain angle while a real one will just shine all over, regardless of what angle!<br /><br />An imperfect stone. Check the overall physical attributes of your stone. A real diamond should have some imperfections in the shape and surface. If you see a perfectly smooth gem, you are probably holding a fake one.<br /><br />These are the things that you need to do effectively determine if the stone that you are looking at is truly a diamond. It would also be a great idea if you take your diamond to a certified gemologist a person who deals with natural and artificially made stones to further identify its true value. If you have an antique gem, make sure that you also consult an antique dealer to achieve a more appropriate appraisal. Now what are you waiting for? Just start following these very simple steps and you can never go wrong! Remember, always be careful when you are about to buy this priceless stone by keeping a keen eye on its physical attributes. Good luck and have fun!

How To Identify a Real Diamond

How To Identify a Real Diamond<br /><br />A diamond is one of the most valuable gemstones known today. It has been used since the ancient times by shamans, leaders of tribes, royalties, dignitaries, dictators, revolutionary individuals, wealthy citizens and the like. Its earliest documented records were found in the Sanskrit texts in India. Due to its cunning features and valuableness, this elegant gemstone has spread all over the world starting from India to China, Ancient Rome, South Africa and Brazil. blood diamond in Africa. As the twentieth century unfolded, chemists and scientists started to create a man made diamond wherein it was chemically produced. This synthetic diamond is worth much lower than the naturally made ones but it is still valuable and can stand the test of time. Identifying a real diamond can be a bit tricky especially when you are new to this kind of thing. Read on to learn more.<br /><br />A refracted image. Get a newspaper, a magazine or a book. Put your diamond on the surface and try to read through it, like a magnifying glass. If you can actually see the letters quite clearly that you can read through the stone, then your diamond is not real. A true diamond dramatically refracts the light so much that you will not be able to see through an image or text at all.<br /><br />Breathe through it. Due to its natural composition, it is a superb conductor of heat. Try breathing through it and check if condensation appears. If it does, then you have a fake diamond.<br /><br />Sparkly or not? Put your diamond up against the light. Carefully scrutinize it by checking how it sparkles in different angles. A fake diamond should only sparkle at a certain angle while a real one will just shine all over, regardless of what angle!<br /><br />An imperfect stone. Check the overall physical attributes of your stone. A real diamond should have some imperfections in the shape and surface. If you see a perfectly smooth gem, you are probably holding a fake one.<br /><br />These are the things that you need to do effectively determine if the stone that you are looking at is truly a diamond. It would also be a great idea if you take your diamond to a certified gemologist a person who deals with natural and artificially made stones to further identify its true value. If you have an antique gem, make sure that you also consult an antique dealer to achieve a more appropriate appraisal. Now what are you waiting for? Just start following these very simple steps and you can never go wrong! Remember, always be careful when you are about to buy this priceless stone by keeping a keen eye on its physical attributes. Good luck and have fun!

How To Clean Your Gold Chain

How To Clean Your Gold Chain<br /><br />The simplest way is to get some mild liquid detergent. The one you use for washing your clothes should do the trick. Put about 2 3 cups of water in a bowl then add some detergent. Put in your gold chain or jewelry and let them soak for a few minutes. This allows the dirt and grime to soften for easier cleaning. After a few minutes, take a used toothbrush in one hand and with the gold chain on your other hand start gently scrubbing in the nooks and crannies of the gold chain or jewelry. After youre satisfied that youve cleaned them enough, rinse the gold chain or jewelry in a separate bowl with clean water. Dry the chain or jewelry with a paper towel and make sure it is completely dried before keeping them away.<br /><br />There is also another way to clean gold chain or jewelry using ammonia but since ammonia is more powerful than detergent, it is best not to use this method.<br /><br /> When doing certain activities, it is best to remove any gold chain or jewelry you are wearing. Activities like taking a bath or washing. Soap dulls the gold finish. When going swimming, chlorine and salt water can discolor your gold.<br /><br /> Keep you gold items separate from other types of gold jewelry to avoid scratches.<br /><br />Gold chain and jewelry should keep for a long time and could also be used as heirloom pieces. But they do get scratched and tarnished so keeping good care of them would prolong their beauty.

How To Clean Your Gold Chain

How To Clean Your Gold Chain<br /><br />The simplest way is to get some mild liquid detergent. The one you use for washing your clothes should do the trick. Put about 2 3 cups of water in a bowl then add some detergent. Put in your gold chain or jewelry and let them soak for a few minutes. This allows the dirt and grime to soften for easier cleaning. After a few minutes, take a used toothbrush in one hand and with the gold chain on your other hand start gently scrubbing in the nooks and crannies of the gold chain or jewelry. After youre satisfied that youve cleaned them enough, rinse the gold chain or jewelry in a separate bowl with clean water. Dry the chain or jewelry with a paper towel and make sure it is completely dried before keeping them away.<br /><br />There is also another way to clean gold chain or jewelry using ammonia but since ammonia is more powerful than detergent, it is best not to use this method.<br /><br /> When doing certain activities, it is best to remove any gold chain or jewelry you are wearing. Activities like taking a bath or washing. Soap dulls the gold finish. When going swimming, chlorine and salt water can discolor your gold.<br /><br /> Keep you gold items separate from other types of gold jewelry to avoid scratches.<br /><br />Gold chain and jewelry should keep for a long time and could also be used as heirloom pieces. But they do get scratched and tarnished so keeping good care of them would prolong their beauty.