Do You Need Caffeine in Your Pre-Workout? The Non-Stimulant Ingredients that Actually Drive Performance

An effective pre-workout supplement boosts your training performance, energy, and focus. While caffeine is a popular pre-workout ingredient, it’s optional. Today’s article will explore performance-driving pre-workout ingredients, including citrulline malate, taurine, beta-alanine, and rhodiola.

Let’s look at:

• The role of caffeine in a pre-workout, and the caffeine-free pre-workout option
• L-citrulline vs. citrulline malate and the benefits
• What does taurine do? The benefits of taurine
• What does beta-alanine do? Beta-alanine benefits
• Rhodiola for adaptogenic support
• How to evaluate a pre-workout without caffeine
• Pre-workout FAQs

What Caffeine Does in a Pre-Workout and Why It Is Not the Whole Story

Most pre-workout supplements contain caffeine. Let’s explore the benefits of caffeine and why a non-stimulant pre-workout is a better choice for some.

Caffeine is a natural molecule found in coffee, tea, and cacao, but it’s also added to soda, energy drinks, and pre-workout supplements as a stimulant. Caffeine acts on the central nervous system, promoting the release of adrenaline (epinephrine) release and increasing fat-burning. (1)

Caffeine supplementation may support exercise performance, including both endurance and strength training. The greatest benefits seem to be for aerobic endurance training when caffeine is ingested prior to training. (1)

While caffeine is a popular pre-workout addition, it’s not the whole story, and research shows that many of the performance benefits are attributed to the other ingredients in a pre-workout supplement. Additionally, some people are sensitive to caffeine and don’t tolerate it well, experiencing energy crashes, headaches, or disrupted sleep.

All in all, caffeine is an optional ingredient, and for those who prefer a non-stim pre-workout, you’ll want to look for appropriate dosages of citrulline malate, taurine, beta-alanine, and rhodiola in a caffeine-free formula. Let’s explore these ingredients next.

L-Citrulline and Citrulline Malate: The Performance Case for Your Biggest Non-Stimulant Ingredient

Citrulline malate (which is the same as l-citrulline and malic acid, listed separately) is the main performance ingredient to look for in a natural pre-workout.

Here’s how it works: L-citrulline is a non-essential amino acid that the body converts to arginine. Arginine increases nitric oxide production, which dilates blood vessels, increasing blood flow and oxygenation to muscles. (2)

Research shows that supplementing citrulline malate increases ATP production during exercise by 34%, improves fatigue, and supports recovery. One randomized controlled trial in CrossFit athletes suggests that those who took citrulline malate before their workout spent significantly more time in zone 4 training. The authors suggest this could be due to citrulline malate’s benefits for aerobic capacity and anaerobic threshold. (3, 4)

A meta-analysis of 8 studies examining citrulline malate supplementation and strength training suggests an ergogenic (enhancing physical performance) benefit. (5)

Citrulline malate benefits may include improved performance during high-intensity and resistance training, as well as enhanced muscle recovery.

Taurine: The Overlooked Ingredient that Supports Endurance and Reduces Fatigue

Taurine is another non-stimulant ingredient to look for in your pre-workout. It is a semi-essential amino acid that’s not incorporated into muscles but rather found inside cells. Taurine health benefits include supporting cellular energy metabolism, genetic expression, electrolyte balance, and more. Taurine supplements have been studied for use in cardiovascular, muscular, and nervous system health. (6)

Because of its cellular mechanisms, taurine also supports exercise performance in both strength and endurance training. A systematic review evaluated the potential of taurine to improve performance based on the taurine dosage:

• 2 grams 3 times per day with exercise can decrease DNA damage
• 1 gram before or after exercise can decrease lactate levels
• 6 grams before exercise increased, glycerol which supports endurance activity
• Even a low dose before strength training can decrease muscular fatigue and increase antioxidants (7)

For a deep dive into this topic, read Taurine Performance Benefits and More.

Beta-Alanine: How it Improves Muscular Endurance Without Any Stimulant Effect

Beta-alanine is a non-stimulant, endurance-enhancing ingredient in pre-workout supplements. It’s a non-essential amino acid that increases carnosine levels inside cells and has a buffering effect during exercise. As a buffer, it helps maintain a balanced pH within cells. The benefits of beta-alanine supplements include mental and physical performance. (8)

A systematic review of 9 studies suggests that beta-alanine supplementation enhances maximal strength and power during training protocols. Additional benefits may include supporting short-duration, high-intensity exercise along with reduced fatigue. (8, 9)

A standard beta alanine dosage is around 3 grams.

Rhodiola Rosea: The Adaptogen that Supports Mental Focus and Fatigue Resistance

Now that we’ve covered these helpful amino acids, let’s discuss Rhodiola rosea, an adaptogenic herb that supports the body’s resilience to stress, including the good stress that comes along with exercise.

Rhodiola supports exercise performance and adaptation by increasing energy use, reducing fatigue, and antioxidant activity that protects muscles. Overall, it may also support energy, cognitive function (including focus), and overall well-being. (10)

Performance research suggests a standardized 200 mg rhodiola dose increases the time to exhaustion and trial times in active males and females. (10)

How to Evaluate a Caffeine-Free Pre-Workout Label and Spot Clinical Doses

The most important thing to look for in a no-caffeine pre-workout is effective dosages of the performance-enhancing ingredients we’ve discussed. Skip any product with a proprietary blend that doesn’t list the dose of each ingredient.

Outwork Nutrition Caffeine-Free Pre-Workout Powder is expertly designed to support performance without caffeine and provides active ingredients in optimal, evidence-based dosages:

• 6000 mg (6 grams) of L-citruline and 1000 mg (1 g) of malic acid (equivalent to 7 grams of citrulline malate)
• 4000 mg (4 g) of taurine
• 3200 mg (3.2 g) of beta-alanine
• 300 mg of rhodiola extract
• No caffeine

The goal of Outwork Pre-Workout Powder is to help you have better workouts every time, and achieve your fitness goals. We do this without proprietary blends, unfamiliar or ineffective ingredients, or bogus claims. Our quality products are made in the USA and 3rd party tested for purity.

If caffeine isn’t a good fit for you, you don’t have to skip a pre-workout supplement entirely. Choose a quality product with performance-enhancing ingredients (and without caffeine) from a transparent brand. Outwork Nutrition always has you covered.

Caffeine-Free Pre-Workout FAQs

Can a caffeine-free pre-workout actually improve performance?

Yes. Many of the performance-enhancing benefits of a pre-workout supplement are attributed to non-caffeine ingredients, including citrulline malate, taurine, beta-alanine, and rhodiola.

What does taurine do in a pre-workout formula?

Taurine supports muscle endurance during both endurance and strength exercise and can help reduce fatigue and support recovery.

What is the clinical dose of beta-alanine for muscular endurance?

The clinical dose of beta-alanine for muscular endurance is 3200 mg or 3.2 grams taken about an hour before a workout.

What is the difference between l-citrulline and citrulline malate?

Citrulline malate is composed of l-citrulline and malic acid. Both citrulline malate and the isolated l-citrulline support performance goals without stimulation.

What does Rhodiola rosea do for athletic performance?

Rhodiola supports adaptation to training, improved energy, and fatigue reduction alongside training.

References

1. Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4. PMID: 33388079; PMCID: PMC7777221.
2. Gonzalez AM, Trexler ET. Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. J Strength Cond Res. 2020 May;34(5):1480-1495. doi: 10.1519/JSC.0000000000003426. PMID: 31977835.
3. Bendahan D, Mattei JP, Ghattas B, Confort-Gouny S, Le Guern ME, Cozzone PJ. Citrulline/malate promotes aerobic energy production in human exercising muscle. Br J Sports Med. 2002 Aug;36(4):282-9. doi: 10.1136/bjsm.36.4.282. PMID: 12145119; PMCID: PMC1724533.
4. Devrim-Lanpir A, Ihász F, Demcsik M, Horváth AC, Góczán P, Czepek P, Takács J, Kimble R, Zare R, Gunes FE, Knechtle B, Weiss K, Rosemann T, Heinrich KM. Effects of Acute Citrulline Malate Supplementation on CrossFit® Exercise Performance: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Study. Nutrients. 2024 Sep 24;16(19):3235. doi: 10.3390/nu16193235. PMID: 39408204; PMCID: PMC11478471.
5. Vårvik FT, Bjørnsen T, Gonzalez AM. Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis. Int J Sport Nutr Exerc Metab. 2021 Jul 1;31(4):350-358. doi: 10.1123/ijsnem.2020-0295. Epub 2021 May 19. PMID: 34010809.
6. Schaffer S, Kim HW. Effects and Mechanisms of Taurine as a Therapeutic Agent. Biomol Ther (Seoul). 2018 May 1;26(3):225-241. doi: 10.4062/biomolther.2017.251. PMID: 29631391; PMCID: PMC5933890.
7. Chen Q, Li Z, Pinho RA, Gupta RC, Ugbolue UC, Thirupathi A, Gu Y. The Dose Response of Taurine on Aerobic and Strength Exercises: A Systematic Review. Front Physiol. 2021 Aug 18;12:700352. doi: 10.3389/fphys.2021.700352. PMID: 34497536; PMCID: PMC8419774.
8. Ong SW, Chen WL, Chien KY, Hsu CW. Dosing strategies for β-alanine supplementation in strength and power performance: a systematic review. J Int Soc Sports Nutr. 2025 Dec;22(1):2566368. doi: 10.1080/15502783.2025.2566368. Epub 2025 Sep 25. PMID: 40995761; PMCID: PMC12466178.
9. Trexler ET, Smith-Ryan AE, Stout JR, Hoffman JR, Wilborn CD, Sale C, Kreider RB, Jäger R, Earnest CP, Bannock L, Campbell B, Kalman D, Ziegenfuss TN, Antonio J. International society of sports nutrition position stand: Beta-Alanine. J Int Soc Sports Nutr. 2015 Jul 15;12:30. doi: 10.1186/s12970-015-0090-y. PMID: 26175657; PMCID: PMC4501114.
10. Tinsley GM, Jagim AR, Potter GDM, Garner D, Galpin AJ. Rhodiola rosea as an adaptogen to enhance exercise performance: a review of the literature. Br J Nutr. 2024 Feb 14;131(3):461-473. doi: 10.1017/S0007114523001988. Epub 2023 Aug 29. PMID: 37641937; PMCID: PMC10784128.