[header] How to maximize your bodybuilding workout [title] Hydrate yourself. [step] You should drink a minimum of two glasses of water (about 16 ounces) prior to your workout as well as throughout. You will know if you are properly hydrated by the color of your urine (darker means improperly hydrated). 
If you don't properly hydrate yourself before and during your workout, you will get dehydrated and the result can be a less effective workout-studies show that performance can decrease up to 15-20 %. Don't risk it-get and stay hydrated.