If you read most pre-workout labels, you'll find that most of them contain some form of caffeine. Maybe you just want a break from caffeine, or you don't enjoy the head-buzzing, slightly jittery feeling caffeine is famous for. Plus, if you train late at night, those caffeine-packed pre-workouts aren't exactly ideal if you want to get a good night's sleep.

If you're looking for a caffeine alternative, you're not alone. There's been a spike in the popularity of caffeine-free pre-workout products that help you maintain energy levels, focus, and endurance, and even support recovery—all without the buzz.

1. Citrulline Malate

Citrulline malate is a new heavy hitter in pre-workouts, and for good reason. Your body converts citrulline to arginine, which dilates your blood vessels to get more blood flowing to your muscles. More blood flow means more nutrient delivery, better waste removal for prolonged exercise, and better pumps!

Multiple studies have reported that people who consume 8 grams of citrulline malate one hour before exercise can perform more reps than people taking just a placebo.[1,2] A study of masters tennis players found that citrulline malate significantly enhanced their hand-grip strength, as well as their peak anaerobic and explosive power (as measured by a 30-second, all-out cycling test).[3]

Not only can citrulline malate significantly improve your performance, it can also help your body tolerate greater stress demands to help you progress more over time.

The 4 Best Caffeine-Free Supplements To Boost Your Workout

2. TeaCrine®

TeaCrine is a bioactive version of the natural compound theacrine, which, technically speaking, is derived from caffeine. But this neuroactive supplement doesn't behave like your typical stimulant. Think of theacrine as a modified version of caffeine: You can get the same kind of performance benefits, but without the jitters and post-workout crash that often comes with caffeine.

A 2017 study showed that a single 200-milligram dose of TeaCrine® had a positive impact on energy levels, fatigue rates, and concentration, when compared to the same dose of a placebo.[4] Also, prolonged TeaCrine use can give you the same kind of benefits you get from caffeine without the habit-forming effects.[5]

The 4 Best Caffeine-Free Supplements To Boost Your Workout

3. Alpha glycerylphosphorylcholine (alpha-GPC)

Alpha-GPC is another newcomer to the world of ergogenic (performance-enhancing) aids. It seems to improve strength and power performance primarily by increasing production of the neurotransmitter acetylcholine. Acetylcholine is a chemical that neurons release to activate muscles.

According to one study, a single 600-milligram dose of alpha-GPC taken 90 minutes prior to exercise can significantly elevate growth-hormone release and increase peak bench-press power.[6] Another study found that while a single dose given one hour before exercise had no effect on the subjects' lower-body force production, significant improvements were seen after six days of supplementation.[7]

4. Betaine

Betaine is commonly found in pre-workout formulas, in part because of its role in improving the body's ability to use creatine. Creatine is an amino acid that increases muscle strength and size, improves recovery and sprint performance, and enhances brain function. Some researchers think betaine may play a role in the production of growth hormone and insulin-like growth factor (IGF-1).

Unlike taking supplements that can have immediate effects on performance, you need to supplement with betaine for around two weeks before you start seeing any noticeable improvements in your strength.

The 4 Best Caffeine-Free Supplements To Boost Your Workout

Participants in a 2009 study who took 1.25 grams of betaine per day for 14 days were able to complete more reps and delay fatigue during high-intensity exercise compared to a placebo group.[8] A second study among resistance-trained men showed that two weeks of betaine supplementation significantly increased their vertical-jump power and isometric squat force.[9] Betaine supplementation has also been shown to improve average and peak power during repeated bike sprints.[10]

Is It Possible to Be Stronger With a Single Dose?

Unlike betaine, which requires the two-week "loading period" to be most effective, the other supplements listed above can deliver results with just a single dose!

To get these immediate benefits, make sure your citrulline malate supplement contains at least 6-8 grams per serving, your TeaCrine® at least 200 milligrams, and your alpha-GPC at least 500-600 milligrams. Dosages lower than these have produced mixed results.

Shop Stimulant-Free Pre-workout Products In Our Store!

  1. Pérez-Guisado, J., & Jakeman, P. M. (2010). . The Journal of Strength & Conditioning Research, 24(5), 1215-1222.
  2. Wax, B., Kavazis, A. N., Weldon, K., & Sperlak, J. (2015). . The Journal of Strength & Conditioning Research, 29(3), 786-79
  3. Glenn, J. M., Gray, M., Jensen, A., Stone, M. S., & Vincenzo, J. L. (2016). . European Journal of Sport Science, 16(8), 1095-110
  4. Ziegenfuss, T. N., Habowski, S. M., Sandrock, J. E., Kedia, A. W., Kerksick, C. M., & Lopez, H. L. (2017). . Journal of Dietary Supplements, 14(1), 9-2
  5. Taylor, L., Mumford, P., Roberts, M., Hayward, S., Mullins, J., Urbina, S., & Wilborn, C. (2016). . Journal of the International Society of Sports Nutrition, 13(1), 2.
  6. Ziegenfuss, T., Landis, J., & Hofheins, J. (2008). . Journal of the International Society of Sports Nutrition, 5(1), P15.
  7. Bellar, D., LeBlanc, N. R., & Campbell, B. (2015). . Journal of the International Society of Sports Nutrition, 12(1), 42.
  8. Hoffman, J. R., Ratamess, N. A., Kang, J., Rashti, S. L., & Faigenbaum, A. D. (2009). . Journal of the International Society of Sports Nutrition, 6(1), 7.
  9. Lee, E. C., Maresh, C. M., Kraemer, W. J., Yamamoto, L. M., Hatfield, D. L., Bailey, B. L., ... & Craig, S. A. (2010). . Journal of the International Society of Sports Nutrition, 7(1), 27.
  10. Pryor, J. L., Craig, S. A., & Swensen, T. (2012). . Journal of the International Society of Sports Nutrition, 9(1), 12.

About the Author

Nick Coker

Nick Coker, MS, CISSN

Nick Coker is a researcher in the Human Performance Laboratory at Georgia Southern University!

View all articles by this author