Hydration? What does this have to do with immunity? Everything!! When the body is dry cells do not get proper nutrition and therefore cannot do their jobs. Proper hydration allows for adequate nutrient uptake by our cells. It also allows for adequate waste removal.
Picture a virus invading your body. Someone in the grocery store with a cold picked up an apple, changed their mind and put it back; now it’s in your fruit bowl! You forget to wash it: now the virus is in the back of your throat. Our bodies are smart! Within a few minutes of ingestion the body detects a foreign entity and goes to work to kill it off before any harm can come.
If the body is properly hydrated the right cells get to the place of infection quicker and the virus is killed off before it has a chance to replicate too many times. The dead cells are carried away in the blood stream where they are filtered into the urinary system to be expelled. Not enough water means slow to no removal.
Exercise = Mobility
In the case of immune system function we are not talking the ability to lift heavy objects or being able to run 5 k in 20 minutes! We are looking at the body`s ability to move fluids: blood, lymph, intracellular/interstitial fluids (intracellular is fluid inside the cells, interstitial is fluid between cells)
Now that we understand why hydration is important we can look at why exercise is important. Lymph is responsible for picking up bacteria and the disposal of it. Unlike blood, lymph does not have its own pump. It relies on the contraction of muscles to transport it around the body.
When we are sedentary the lymph travels very slowly, often pooling in the extremities with no way of disposal. An active lifestyle allows for maximum motility of lymph throughout the body. Which in-turn speeds up the removal of waste products from the body with the help of water of course!