Looks to me like you just copy and pasted a wikipedia page and passed it off as your own knowledge....
What he is referring to about water to the muscles is a basic way to describe it.. A pre workout supplement works on the premise that it will cause a state of vasodilation, use your bff wikipedia to keep up if you cant.. This vasodilation occurs at whatever place in the body is being worked, doesn't even have to apply to working out.... How do you think you get an erection? Increase in blood flow... By allowing this increase in blood flow, you are allowing the increase in nutrients available to that area as well, due to the dilation.. Also we all know the importance of drinking plenty of water, and staying hydrated... Also drinking plenty of water helps to lower the viscosity level of blood( why do you think people get headaches when they travel to altitude? blood is to thick) allowing it to flow in and out of the cells easier, thus shuttling nutrients in and faster(also why do you think it is important to take an aspirin if youre having a stroke, the aspirin lowers the viscosity of the blood causing the clot to decrease allowing blood flow to the brain).. Never mind that atp nonsense, you want to work out and get bigger or do you want to scientifically formulate the product.... So its not necessarily allowing more water into muscles but it is allowing the blood to flow in and out of the affected tissue easier.. This all reacts on a partial pressure of the nutrient in the blood versus the cell... if the partial pressure is greater in the blood stream than that in the cell it will diffuse through until it is equalized or saturated... More blood flow=more readily available nutrients << it works in reverse as well... after the muscle exerts itself and releases the by-product it then has a greater partial pressure of product in the cell than in the blood, therefore it will diffuse back in to the bloodstream, and if that blood stream is more efficient due to having a lower viscosity, due to being properly hydrated the entire system will work better... Do your research..
