Muscle is primarily made up of water, so keeping hydrated is essential for maintaining maximum muscle cell volume, and also aids in muscle growth. Failing to keep your body hydrated will restrict the amount of muscle growth you will achieve from training.When the body becomes dehydrated, it takes water from the muscles, making the body go into a muscle wasting  state. It is crucial therefore to drink plenty of water to keep the muscles working at maximum efficiency.Caffeine drinks, such as tea, coffee and most fizzy drinks, contribute greatly to dehydrating the body. If you do like a cup of coffee in the morning, it is essential to balance this out with plenty of water.