The human body is made up of roughly around 50 percent water. This is why we need to drink lots and lots of it. Our cells require water to be activated. Water helps jumpstart the transportation of materials throughout the body. It acts both as a solvent and lubricant. It helps regulate our temperatures and it plays an important role in keeping our heart pumping. Put simply, regular intake of water makes us who and what we are.
Unfortunately, most people don't drink enough water, which is just wrong. You need water and lots of it especially when you work out a lot. Normally, people lose around half a gallon to two gallons of water a day, most of which is through perspiration. When you sweat and lose water, your body also loses precious electrolytes, and the lack of electrolytes can cause many issues including cramping.
Cramps, though, are the least of your worries. Your heart just can't pump efficiently if you don't drink enough water. As a result, your blood volume drops, and because there's less blood in your muscles, they get less oxygen and blood sugar, all the while your core temperature rises much faster, which means, among many other things, you get tired easily. Your body generally doesn't work like the well-oiled machine that it should when you're dehydrated. Your hand-eye coordination and decision-making skills are both affected by lack of water.
Put simply, if you don't drink enough water, your body has to work extra hard only to achieve much less.
The next time you go out for a run or a quick session at the gym, always remember to bring a water bottle, drink it, and refill it many times. Your power, endurance, thinking, and health all rely on how much water you take in.