Pre-workout jitters are common, and it can often be a formula problem. Caffeine itself is one of the most well-researched performance ingredients on the planet, with solid evidence behind its ability to improve focus, endurance, and power output [1]. However, for some people, high caffeine doses without anything to counterbalance it can cause shaky hands, an elevated heart rate, and anxiety. After one bad experience, the expectation of jitters alone can be enough to bring it on again. At Clean Nutrition, we know it doesn't have to be that way.

What Actually Causes Pre-Workout Jitters?

Caffeine works by blocking adenosine receptors in the brain (the receptors that make you feel tired), and stimulating the central nervous system (CNS) to increase muscle function and 'drive'. That's the good part. The problem is that for some people, high caffeine doses (typically above 200–250mg) can overwhelm the sympathetic nervous system (your 'fight or flight' response). That's when you get the elevated heart rate, the anxiety, the shakiness.

A lot of pre-workouts are on the higher-end of the caffeine spectrum, they pile in 300mg or more so that you feel the stimulant hit, hard. But more isn't always better, especially if you're consuming other sources of caffeine alongside your pre-workout – more on this later in the blog.

The fix isn't always zero caffeine. It's smarter caffeine.

The Ingredient That Changes Everything: L-Theanine

L-theanine is an amino acid found naturally in green tea. It's been studied extensively for what it does alongside caffeine: it takes the edge off.

Research has shown that L-theanine and caffeine together produce better cognitive performance than caffeine alone, with notably lower ratings of anxiety and jitteriness [2, 3, 4]. The combination improves focus and reaction time while reducing the "wired" feeling that puts people off stimulant-based supplements.

Our pre-workout contains 175mg of caffeine and 175mg of L-theanine — a 1:1 ratio. That's not a coincidence. It's a ratio that's been studied, and it's what gives you clean, focused energy without the jitters.

Why 175mg of Caffeine Works

175mg is a solid, performance-relevant dose. It is enough to meaningfully improve focus, endurance, and power output for most people, without tipping into the range where side effects tend to show up. Higher doses (250–350mg) work well for plenty of athletes, particularly those who are bigger, more caffeine-tolerant, or doing longer, higher-intensity sessions. But if you've found those doses leave you feeling anxious, over-stimulated, or unable to sleep after an afternoon session, 175mg caffeine combined with theanine is likely a better fit. It's about finding what works for your body, not chasing the biggest number on the label.

Caffeine Through the Day: How It All Adds Up

Many people taking pre-workout are also coffee drinkers. At 175mg per serve, our pre-workout could still be used on the same day as enjoying a coffee. A flat white or long black typically contains around 100–150mg of caffeine, so even if you've had one earlier in the day, you're still under the 400mg daily limit that health guidelines consider safe for healthy adults [5]. That headroom is one of the reasons we chose 175mg over a higher dose.

Worth mentioning is that timing matters too. Caffeine has a half-life of roughly five to six hours [6] — meaning half of what you consumed is still active in your bloodstream five to six hours later. Take a 175mg pre-workout at 4pm and you've still got around 87mg circulating at 9 or 10pm. That's enough to reduce sleep quality even if you manage to fall asleep, partly because caffeine suppresses the deep, restorative sleep your body uses to repair muscle tissue [7]. Our honest recommendation: take your pre-workout before midday where possible, or no later than early afternoon. Individual clearance rates vary: genetics, hormonal contraceptives, and some medications can all extend how long caffeine stays in your system, so if evening training is your only option, pay attention to how your sleep responds.

We Use Natural Ingredients

Our pre-workout uses natural caffeine (sourced from coffee bean), natural flavour, and thaumatin as the sweetener (a natural protein extracted from the katemfe fruit). This means you get a clean flavour with no added sugar and no artificial aftertaste.

What Else Is in the Formula

L-Citrulline (3000mg)

L-citrulline converts to L-arginine in the kidneys, which the body uses to produce nitric oxide. This can result in better blood flow to working muscles, more endurance, and less soreness after training [8]. It's also one of the most commonly under-dosed ingredients in pre-workout. A lot of labels show it; a lot of formulas don't put in enough to matter. Ours has 3000mg, which falls within the clinically studied range.

Beta-Alanine (1600mg)

Beta-alanine converts to carnosine at the muscle. Carnosine buffers the build-up of acid in your muscles during intense exercise, which means you can push harder for longer before fatigue forces you to stop [9]. It's particularly useful for high-intensity, repeated-effort training, think CrossFit, Hyrox, intervals, and heavy lifting circuits.

One thing worth knowing: beta-alanine causes a temporary tingling sensation, usually on the face, neck, or hands. It's called paraesthesia and it's a harmless, normal response to the ingredient, not a sign that something's wrong. It fades within about 30 minutes. We mention it on the label because that's what we do.

Beta-alanine works best when taken daily, so it also available as a single ingredient product within our essentials range. Learn more about beta alanine in our blog What Does Beta-Alanine Do? Benefits, Dosage, Performance Effects & Science.

No Fillers, No Bulking Agents

The full ingredient list: L-Citrulline, Beta-Alanine, Malic Acid, Citric Acid, Natural Flavour, Natural Caffeine, L-Theanine, Barley Grass, Thaumatin, Silica.

That's it. 6.3g per serve. Nothing in there to pad out the weight or spike the numbers. Every ingredient has a reason to be there. We keep it pure and simple.

Who This Formula Is For

If you've avoided pre-workout because a previous one left you feeling awful: this is the one to try.

It's also well-suited to:

People who like caffeine but have found high-stimulant products too much
Women, who on average have a lower perceived caffeine threshold than men [10]
Those who consume another caffeine source on the same day as using pre-workout (within reason)
Beginners who want to support their training without going overboard on stimulants

If you're training hard and want something to sharpen focus, support endurance, and actually enjoy taking, Clean Nutrition Pre-Workout it's designed for you.

Ready to Give It a Go?

Shop Clean Nutrition Pre-Workout

Key facts: 30 serves per pack. Made in New Zealand from local and imported ingredients. Priced for real Kiwi lifestyles.

No junk. No jitters. Just what you need.

Frequently Asked Questions

Will I feel the beta-alanine tingling? Probably, yes — at least at first. Beta-alanine causes a temporary tingling or flushing sensation that usually shows up within 15–20 minutes of taking it. It's harmless and fades within half an hour. Some people find it actually helps them feel like something is working. Others don't love it. Either way, the tingling feeling passes with time.

How does this compare to just having a coffee before training? Coffee gives you caffeine with no additional performance ingredients. Our pre-workout gives you the same caffeine level as a strong coffee, plus L-theanine to smooth the effect, citrulline to support blood flow and endurance, and beta-alanine to help buffer muscle fatigue. It's a more complete formula for training.

Can I take it every day? You can, though taking occasional breaks from caffeine-containing products is generally a sensible idea. After a few weeks of daily use, tolerance to caffeine builds and the effects become less pronounced.

References

[1] Grgic J, et al. Wake up and smell the coffee: caffeine supplementation and exercise performance — an umbrella review of 21 published meta-analyses. Br J Sports Med. 2020;54(11):681–688.

[2] Haskell CF, et al. The effects of L-theanine, caffeine and their combination on cognition and mood. Biol Psychol. 2008;77(2):113–122.

[3] Giesbrecht T, et al. The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness and reduces fatigue relative to caffeine alone. Nutr Neurosci. 2010;13(6):283–290.

[4] Owen GN, et al. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008;11(4):193–198.

[5] European Food Safety Authority. Scientific opinion on the safety of caffeine. EFSA J. 2015;13(5):4102.

[6] Fredholm BB, et al. Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev. 1999;51(1):83–133.  

[7] Drake C, et al. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013;9(11):1195–1200.

[8] Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010;24(5):1215–1222.

[9] Hobson RM, et al. Effects of β-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012;43(1):25–37.

[10] Domaszewski P. Gender differences in the frequency of positive and negative effects after acute caffeine consumption. Nutrients. 2023;15(6):1318.