Water is the most important factor in sports nutrition. It makes up 60% of body weight and is involved in almost every bodily process. Your body cannot make or store water so you need to replace the fluids you lose through sweating. If you allow yourself to become dehydrated, your blood will thicken, making your heart work harder. Also, when you're dehydrated while exercising you will experience premature fatigue and will likely end up with a dull headache.

In most cases pure water is best for hydration. Everyone should drink at least two quarts (eight cups) of water each day and athletes need more. On very hot, humid days, or for longer events fuel up with a sports drink (containing electrolytes and carbohydrates) rather than water. This will help replace electrolytes lost as well as help your body retain more fluid.