The Effects of Dehydration on Muscles
What is Dehydration?
Dehydration, at least for this purpose, is defined as the loss of bodily fluids. It occurs when an organism loses more fluids than in takes in. Our body, although a complex organism, is made up up almost 2/3 water; present both in and around cells, and blood vessels.
Effect of Dehydration on Muscles
The body relies heavily on water to maintain healthy functions among it's various systems. Severe dehydration can precipitate negative changes in health such as decreased cardiovascular efficiency, renal impairment, and fatigue. When exposed to elevated temperatures and high levels of humidity, performing any type of strenuous physical activity will cause a drop in body mass, mostly due to the fact that your body is approximatley 70% water. On any given day, assuming that humidity is high, an individual performing excess physical activity can lose a small portion of their body mass. If the loss is 15-20% of their body mass, or approximatley 20-30% of their total body water, death is almost certain. This, however, is not always the case. If any of the conditions for dehydration are right, it can even be contracted in temperate weather. Water loss is not the only cause of mild dehydration. Dehydration has been proven to decrease the lactate threshold while also increasing thermal and cardiovascular stress. Glycogen use and exertion of the muscles has also been noted in these cases. All of these may lead to reduced endurance performance in both hot and temperate climates.
Man with severe dehydration
The Process of Dehydration
As with all mechanisms, there is a process by which dehydration takes effect. A series of various occurrences must take place in order for dehydration to come about, all of which are seemingly directly related to the temperature and humidity. Blood must circulate to the muscles to supply oxygen and certain substrates in addition to circulating to the surface of the skin to release heat. The muscles take priority in this matter, making it harder on the body to release heat via the skin. As temperature increases, the rise of blood to the surface of the skin precipitates an increase of fluid loss through sweat. Because of this sweat, the volume of plasma running throughout the body is decreased as well, thus triggering the onset of dehydration. Dehydration is caused by factors such as impeding of thermal regulation, the alteration of water across the muscle membrane, and interference in the “actin-myosin cross bridge formation”.
Controversy Over Credible Testing
There has been much controversy over testing for dehydration, specifically in muscles. Although there is a genre of tests definitively geared towards this specific topic, their credibility is often questioned. Much of the research done on muscle fatigue includes tests that don’t allow the muscles to cool properly, thus corrupting any data and making it impossible to separate the results from the elevated muscle temperature. This same mentality is carried over into another similar test. When muscle heat is elevated, as to cause dehydration, subjects are not given the proper amount of rest to offset the muscle fatigue they are enduring. This, too, corrupts data and makes it impossible to ascertain any usable figures. In reducing water intake to test dehydration factors, there is also commonly a reduced food intake, leading to changes in muscle glycogen content and in the acid–base status of the muscle. As with all tests, there is room for error. However, it is very hard, if not impossible, to regulate control factors such as muscle glycogen content, and specific time needed for a person to recover from muscle fatigue. Much of it depends on the person being tested. Although you can regulate food and water intake, metabolism is a factor that cannot be regulated as well. The rate at which a person digests and processes food and liquids is directly related to their hydration levels.
Illness Caused By Dehydration
With water deprivation comes many side effects and symptoms, some of which can evolve into long-term illnesses if not treated properly. Because the body relies so heavily on water to maintain its basic functions, the lack thereof can cause detrimental effects. The human body develops reactions to water deprivation, most of which are chronic illnesses.
Such illnesses include:
- Bronchitis (respiratory disease)
- Asthma (respiratory disease)
- Lupus Erythematosus (connective tissue disease)
- Multiple Sclerosis (autoimmune disease)
and it has even been linked to some cancers, however this is not supported.
As you can imagine, there are exacerbating factors associated with most of the more serious diseases listed above. However chronic dehydration can cause mild every day symptoms people will struggle with, and not even know it. Dehydration can specifically cause illness in muscles as well. Chronic pain in muscles and joints is common, rheumatoid arthritis, and heart pains are also associated with dehydration, however it highly depends on the extent to which the subject is dehydrated.
In order to test just what effect dehydration has on muscle strength and overall wellness, I formulated a plan in which I followed for seven days. I tested it twice, for a total of 14 days. My plan consisted of a workout regiment designed to test specific muscle strength and endurance while being both full hydrated and mildly dehydrated. I kept a log each day, detailing the symptoms I was experiencing and how strong my muscles were compared to being fully hydrated. The endurance aspect consisted of running one mile outside on the track of York College. I used a method of dehydration used by many body-builders in the week preceding a fitness competition. In essence, this achieved by regulating the amount of water intake, while also monitoring the types of food you eat. Fruits and vegetables generally tend to retain larger quantities of water. Salt and carbohydrate intake also play important roles in dehydration as well. There is a direct correlation between the amount of salt in your system and the extent to which one is dehydrated.