Our bodies are 60 – 70% made up of water, which is almost 2/3 of our body weight. We lose water through sweat, urine, faeces and in the air we breathe out. It is the main component in blood cells, which carry oxygen, nutrients and waste around the body. Water in the blood also maintains temperature regulation by absorbing heat produced during exercise. Almost every function in the body takes place through water and it acts as a solvent removing nutrients, antibodies, hormones and oxygen through the blood. In order to maintain homeostasis we must consume optimal amounts of water everyday otherwise our bodies could not function efficiently.
Water is lost everyday through our regular activities and exercises, but also through our body functions. Elimination of waste is where we lose most water, which includes urination and excretion. As our body is made up of water and we consume water and fluids during the day there is a limit to how much fluids we can consume. When we reach the limit of fluid consumption our body uses urination to get rid of excess fluid but waste products also. If we do not drink enough water the amount of urine being expelled decreases and the urine becomes concentrated. Although when we become dehydrated the body rations and recycles water, and all fluid losing functions are reduced meaning waste that should have been carried out of the body by the fluid is now traveling into tissues and muscles instead.
Water plays a key role in temperature regulation within the body. During exercise water in the blood absorbs the heat and then carries it to the skin where it is lost in the air as sweat. Water in the form of sweat helps to cool the body when it evaporates on the surface of the skin. When we do not have enough water to regulate body temperature in the initial stages we become dizzy and light headed, suffer from nausea and in more serious cases suffer from heat stroke, hypothermia and can even die.
The brain is around 90% comprised of water and controls the functioning of the body. Increased intake of water means that nerve impulses can travel faster therefore promoting better thinking and more activity which is particularly important for sport. However on the other hand if we do not consume enough water we suffer from decreased energy in the brain causing headaches, confusion and tiredness.
The kidneys play a key role in maintaining homeostasis in the body as they are constantly filtering the blood, gathering waste and expelling it from the body in urine. When we do not consume enough water our bodies are unable to flush out water filled with waste and therefore the kidneys have to work double time to recycle the waste filled water. If the kidneys are experiencing high levels of stress the liver acts as a buffer to some of the kidneys work. However constant stress can cause serious permanent damage to the kidneys. Food also needs optimal amounts of water in order to digest. Water carries nutrients to cells in the blood and through cells via osmosis which is why increased water consumption decreases feeling of constipation and heartburn or indigestion.