Pre-Workout is used as a caffeine source before workouts and can also provide other ingredients to encourage muscle endurance, growth, and recovery.
**WARNING: Common side effects of too much caffeine are headaches, dry mouth, and cramping. If you are new to pre-workout supplements, start with a choice listed under "sensitive to caffeine". If you buy a pre-workout and you get a headache, (1) make sure you're drinking 80-100oz of water a day (2) try a smaller serving. Next time you use it only do 1/2 scoop.