Caffeine-Based Preworkout Supplements: Friend or Foe?

Flipping through popular fitness magazines, you may have seen the ads for products like N.O.-Xplode, Jack3d, Black Powder, Hemo-Rage and my favorite, Assault.


Flipping through popular fitness magazines, you may have seen the ads for products like N.O.-Xplode, Jack3d, Black Powder, Hemo-Rage and my favorite, Assault. While these may sound like new band names on the Warped Tour, they are actually preworkout supplements that you could find at your local vitamin/sport supplement store. They are coupled with tag lines like “Amazing Pumps!” or “Unleash Hell in Your Workout!” and “Ignite Yourself!” These products claim to increase performance in workouts, providing more mental focus, energy, endurance and blood flow to extremities, but what do they really do? How do they work? And what are the real risks and benefits of consuming them?

Most of these supplements are based on caffeine, containing anywhere from 100 to 300 milligrams of caffeine in a serving. Just to compare, there are about 90 milligrams in a strong cup of coffee. When caffeine enters the body, systems start working harder to evacuate the substance from inside. There are events in the body like increased heart rate, increased blood pressure, the kidneys working harder causing frequent urination and mental excitement. Make no mistake, caffeine is a powerful drug and has been associated with such silent killers such as hypertension. As with many drugs, people tend to develop tolerances and become desensitized to the effects of caffeine, resorting to larger doses to achieve a mental high. Stress on the adrenal glands due to chronic caffeine use becomes high and can lead to symptoms such as adrenal fatigue.

Having said that, there are many advantages to using preworkout supplements. I myself use these products, but I try to do it with an understanding and respect of their power, and a strategic application to my training. These products work. There is definitely a performance advantage when applied in the correct doses to the correct training. The University of Connecticut performed a study clearly showing an increase in bench press and grip strength for groups using preworkout caffeine stimulants. Research has confirmed the increased mental focus and acuity from the use of caffeine. For populations that are trying to loose weight, caffeine is an appetite suppressant and has been shown to increase both lipolysis (breakdown of fat) and thermogenesis (calorie burning).

These preworkout products are often stacked with other substances such as arginine, a powerful vasodilator, increasing blood flow, producing a “pump.” This is done with the intent that increased blood flow will increase performance.

Many of these products may contain stimulants that are banned in significant doses for competitions by organizations like the USOC and the NCAA. I would recommend being careful and cross-referencing all the ingredients with a banned-substance list in your sport.

Due to the fact that these substances increase heart rate and blood pressure, I would not recommend them for activities where heart rate is already elevated such as endurance events and metabolic (lactic) training. I have heard of many athletes that claim to feel like they are drowning due to overuse of caffeine in conditioning workouts and end up with nausea and vomiting.

To avoid becoming desensitized to the effects of these products I would recommend using them sparingly. I only use my preworkout go-go-juice for a long and heavy strength-training session to help with the mental fatigue that often accompanies such a stressor. Cycle products on and off. Take a break after a few weeks and let your body normalize for a while with no or less caffeine. This will help you avoid adrenal fatigue. Remember choosing the right supplements, like choosing the right diet, can assist you in your training, but in the end you are the determining factor in your success in training.

Here is a quick overview of all the pros and cons of preworkout stimulants:


  • Increased focus
  • Increased energy
  • Increased strength
  • Increased fat burning
  • Weight loss


  • Potential increased blood pressure
  • Potential adrenal fatigue
  • Possible drug test failure
  • Potential feeling of racing heart coupled with nausea and vomiting