We ship worldwide from the USA and UK
4 Gauge Blog : Load Up Your Guns

L-Theanine Pre Workout: Everything You Need to Know

Categories :

You’re here because you’re looking for the best pre workout ingredients on the market. You’ve been researching the advantages of each workout-enhancing supplement and in your mind you’re piecing together your dream team of gym-crushing nutrients.

Good. Because it’s only through researching and boosting your knowledge that you’ll ensure you get the best products.

In this article we’ll take a look at L-theanine – a cognitive enhancer found in tea leaves.

Is it an ingredient that you should add to your pre workout stack?

Let’s take a look…

What is L-Theanine?

L-theanine is an amino acid found naturally in tea leaves. Although all types of tea contain the nutrient, it is most commonly associated with green tea and this was the first know source of the compound.

It is an analogue of another amino acid called L-glutamine because it shares a very similar chemical structure.

And much like this neurotransmitter, it increases the release of gamma-aminobutyric acid (GABA) – a chemical known for its ability to promote relaxation, calm and inhibit central nervous system activity.

That means that adding L-theanine into your stack has a calming and relaxing effect, but also promotes focus, attention and memory too.

If it’s relaxing why is L-theanine in a pre workout?

Surely the idea of a good pre workout is to ramp up your nervous system so that you can lift heavy, run faster and crush your gym sessions?

L-theanine works synergistically with stimulants.

When it is is combined with caffeine it provides a nootropic effect – a supplement used to boost cognitive ability.

The combination of both nutrients might seem a strange combination at first, but think about it – they both derive from tea leaves where they exist naturally together.

Smart caffeine – the key to better focus

If you’ve ever had a crash from coffee or strong caffeine pills, you’ll know how horrible it can be.

You feel jittery and nervous, nauseous, anxious. Your heart feels like it’ll burst from your chest and you feel sweaty, warm and dizzy. If anything it makes your workouts less productive.

The combination of L-theanine and caffeine is often referred to as smart caffeine because while caffeine raises energy, heart rate and blood pressure; L-theanine helps to use these stimulatory effects productively.

It’s a kind of chaperone, making sure that the energy boost from caffeine goes to where its needed – without jitters or a loss of focus.

If caffeine was the rifle, L-theanine is the scope. It helps you to zone in on where you need energy the most and target it for maximal effect.

A field of green tea leaves close up on a sunny day
  • Key Point: L-theanine helps to balance out the stimulatory effects of caffeine, targeting it to where you need it the most.

The Science – L-theanine and Better Workouts

Smart caffeine boosts cognition

A study from Biological Psychology [1] found that combining caffeine and L-theanine was found to boost cognition – and help to make the effects of energy and concentration last longer too.

In the randomized, placebo-controlled study, the effects of 250 mg of caffeine and 150 mg of L-theanine were tested in isolation for their effects for various cognitive markers.

They were also then tested together to see if they did in fact have a ‘smart’ effect.

What did the researchers report?

  • Reduced mental fatigue
  • Enhanced memory
  • Better reaction time
  • Reduced headaches and tiredness

The results showed clearly that adding L-theanine to a caffeine-based pre workout helped to target its stimulatory effects much better than caffeine alone.

L-theanine reduces blood pressure increase caused by caffeine

One of the side effects of high doses of caffeine is that it elevates your blood pressure as well as heart rate and energy levels.

But combining the two nutrients into a smart caffeine combination has been shown to reduce vasoconstriction and improve blood flow within the brain, helping to maintain a healthy blood pressure.

From the journal Psychopharmacology [2], combining 75 mg of caffeine with 50 mg of L-theanine was shown to completely eliminate the vascular constricting effects of caffeine.

And it did this without negatively effecting either its stimulatory effects, or the behavior of the volunteers.

Smart caffeine improves performance

One of the main reasons you’ll be wanting to take a pre workout is to boost performance.

And you’re in the right place because studies also show that smart caffeine ramps up cognitive performance – much better than caffeine alone [3].

Young female athlete performing burpees on a medicine ball in the gym
  • Key Point: L-theanine is an amino acid supplement that can protect your nervous system, enhance mood and help target the effects of caffeine to boost focus and attention.

Other Benefits of L-theanine

The reason why this brain-boosting amino acid is added yo your workout should be clear by now – it helps target the stimulatory effect of caffeine and limit any unwanted side effects.

But that’s not all it can do.

Reduces anxiety

A study from Kimura et al [4] found that when 12 volunteers were given a mental arithmetic task as a stress-inducing problem, L-theanine was able to reduce markers of psychological stress by 50%.

The volunteers’ heart rate was also reduced, showing that the supplement had the ability to cause relaxation, even during times of stress.

Promote overall feelings of well-being

When 40 patients participated in an 8-week double-blind, randomized intervention study of 400 mg of L-theanine per day, the supplement was able to not only reduce feelings of anxiety, but improve subjective well-being too [5].

Improves sleep quality

Granted, this was a study that looked at the effects of L-theanine in isolation and not combined with caffeine, but it’s useful to know how potent its calming effect really is.

In young men with ADHD-related sleep disturbances, 400 mg over a 6-week period helped to improve sleep quality and efficiency by reducing time spent waking up through the night [6].


L-theanine is an amino acid found naturally in tea leaves. It is a potent cognitive enhancer that helps target the stimulatory effects of caffeine, pushing them to where you need them the most.

As a pre workout ingredient, you’ll really benefit from adding this nutrient to your stack – particularly if you lack focus or motivation when training hard.

Smash Your Workouts With 4 Gauge

4 Gauge is an exhaustively researched, all-natural pre workout designed to rip the lid off your gym sessions, sports games or workouts.

Packed with performance-enhancing nutrients such as caffeine, L-theanine and creatine, 4 Gauge will take your training to a completely new level.

  • Smash your workouts – feel your nervous system firing on all cylinders
  • Cell-splitting muscle pumps – harness the power of vasodilation and deliver more nutrients to your muscle cells
  • Determination like never before – feel unparalleled focus and motivation
  • Relentless energy – train for longer without fatigue


  1. Haskell, CF et al. The effects of L-theanine, caffeine and their combination on cognition and mood. Biol Psychol. 2008; 77(2): 113-22
  2. Dodd, FL et al. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology. 2015; 232(14): 2563-76
  3. Owen, GN et al. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008; 11(4): 193-8
  4. Kimura, K et al. L-Theanine reduces psychological and physiological stress responses. Biol Psych. 2007; 74(1): 39-45
  5. Ritsner, MS et al. L-theanine relieves positive, activation, and anxiety symptoms in patients with schizophrenia and schizoaffective disorder: an 8-week, randomized, double-blind, placebo-controlled, 2-center study. J Clin Psychiatry. 2011; 72(1): 34-42
  6. Lyon, MR et al. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011; 16(4): 348-54

Lock 'N' Load
Order now 128 bit encryption
4 Gauge - Lock 'n' Load