With a passion like yours, you can't just use any preworkout supplement. The Cellucor C4 Extreme Energy Preworkout Powder is formulated specifically for the serious athletes who crave that extra rush. It contains 300 milligrams of caffeine per serving, which is twice as much as what's found in the C4 Original blend. As you sip on the sweet, fruity flavor, your body will come alive with plenty of energy, endurance and focus.