When you think about a pre-workout, chances are your mind is laced with thoughts of a racing heart and adrenaline pumping.

Something to energize you so hard that you’ll power through your workout like never before, filled with focus, concentration, and drive. It’s the “usual” response that people strive for when they knock back a scoop or two of pre-workout.

But while caffeine can have some pretty good benefits for your training sessions, if you’ve ever taken too much of a high-stim pre-workout, you know it can also be detrimental to your performance.

There's a fine line between overdoing it and not doing enough. And if we’re talking about the long-term effects of high-stim pre-workouts, that goes into a whole other realm of topics.

If you’ve thought about cutting back on the stimulants but you’re not 100% convinced, we’re talking about low caffeine pre-workouts and why sometimes less is more where caffeine is concerned.

And if you fall into the camp that believes low-stim training aids don’t serve a purpose in the fitness world, it’s time to rethink your train of thought.

How Caffeine Works

After consumption, caffeine is rapidly absorbed directly from the gut into the bloodstream with plasma concentrations peaking anywhere from 30 to 120 minutes after ingestion 1.

Caffeine's primary mechanism of action and its effects on performance largely result from the central nervous system (CNS), although other mechanisms of action have been suggested. Some of those include increased myofibrillar calcium availability and optimized exercise metabolism 1.

Caffeine has been shown to spare glycogen breakdown, enhancing endurance performance 2 through the ergogenic effects of post-consumption, adrenaline-induced enhancement of free-fatty acid (FFA) oxidation. Free-fatty acids are a more energy-dense fuel source than glycogen and, thus, provide more energy to fuel high-intensity activity.

Due to its property as an adenosine antagonist 3, caffeine increases CNS alertness and reduces fatigue—one of the main draws where exercise is concerned. The structure of caffeine closely resembles that of adenosine, which means that it can bind to cell membrane receptors for adenosine and block their action.

Adenosine receptors are concentrated in several tissues, including the brain, heart, smooth muscle, adipocytes (fat cells), and skeletal muscle. Because adenosine is largely responsible for inducing drowsiness, blocking adenosine from binding and replacing it with a CNS-stimulating compound boosts energy and alertness and prevents fatigue.

But caffeine may also have some intracellular actions, although these are less well-known. One of the major appeals of caffeine consumption pre-workout is the secretion of adrenaline (epinephrine) 2, 4. By boosting levels of catecholamines, caffeine could cause secondary metabolic changes that may be beneficial for exercise.

However, what’s interesting is that we can adjust to caffeine - often called habituation. If you’ve ever consumed coffee or pre-workout and, a few months later, found that the same dosage isn’t doing anything for you, you’ve experienced caffeine habituation at its finest.

Rodent studies show that with daily intake of caffeine (10mg/kg/day), the body responds by increasing the number of binding sites for adenosine in the brain 5.

Therefore, daily intake of caffeine can result in more newly created adenosine receptors, reducing the blocking-action of caffeine and its ergogenic exercise effects (i.e. habituation). Because of this, it takes more caffeine to achieve the same effect.

The Benefits Of Caffeine

There’s no question that stimulants have their place in the fitness world. There’s an abundance of research touting the benefits of caffeine for everything from strength and power to endurance, but why exactly do we crave stimulants when we’re about to hit a lift?


The most common reason for adding caffeine to a pre-workout is obvious—it boosts energy. Like we just talked about, caffeine is a potent adenosine antagonist, meaning it blocks adenosine receptors in the brain to prevent fatigue.

Caffeine increases energy metabolism throughout the brain, as well as activating noradrenaline neurons that influence the release of dopamine, the “feel-good” hormone.

However, research attributes many of the alerting and arousal effects of caffeine to the action of the methylxanthine on serotonin neurons 6.

Methylxanthine has been shown to induce dose-dependent response increases in locomotor activity, but the influence of caffeine on learning, memory, performance, and coordination are more likely related to methylxanthine’s effect on arousal, vigilance, and fatigue.


If you’re looking to increase focus and drive during a workout, caffeine will do it.

That’s because caffeine consumption influences the central nervous system and boosts the brain's production of dopamine, which plays a major role in regulating the ability to focus and maintain concentration.

Specifically, it enhances dopamine signaling in the brain by antagonizing adenosine A2A receptors (A2AR) 7.

Adenosine plays an important role as a modulator of both dopamine and glutamate neurotransmission.

Acting on adenosine A1 receptors localized in nerve terminals, adenosine ultimately inhibits the release of dopamine and glutamate. It also reduces dopaminergic neurotransmission via specific antagonistic actions between adenosine and dopamine receptors.

Because caffeine acts as an endogenous adenosine antagonizer, studies suggest it could facilitate dopaminergic neurotransmission by stimulating dopamine release and/or by intensifying the effects of dopamine receptor stimulation 8.

May Spare Muscle Glycogen

For anyone looking to take their performance and recovery to the next level, caffeine’s glycogen-sparing effects can be fantastic. Studies show that caffeine may spare glycogen by increasing serum concentrations of free fatty acids (FFA) available as an energy substrate.

The evidence behind this one isn’t concrete, but by delaying muscle glycogen depletion, exercise can be prolonged and allow the individual to go harder, longer, and perform more reps before hitting fatigue.

Fat Burning

The link between caffeine consumption and fat oxidation is trivial and there’s research supporting the role of caffeine for a couple of different mechanisms.

The increase in energy expenditure and changes in plasma substrate use after consuming caffeine may be in part caused by an increase in sympathetic nervous system (SNS) activity. An increase in SNS activity causes increased secretion of catecholamines, which subsequently increases lipolysis 9.

Other studies suggest that caffeine could boost lipolysis by inhibiting the cyclic nucleotide phosphodiesterase, the enzyme responsible for catalyzing the conversion of cyclic AMP to AMP. As tissue levels of cyclic AMP increase, hormone-sensitive lipase is activated, which stimulates lipolysis.

Regardless of the mechanism, there’s a substantial amount of research supporting the link between caffeine and fat and weight loss; it’s one of the primary reasons why caffeine is added to fat burner supplements.

The Downside Of Heavy Stimulant Use

The draw of high-stim pre-workout supplements designed to increase alertness and maximize focus can be enticing, but most people don’t stop to think about the not-so-immediate effects.

For some people, the reaction they get isn’t exactly what’s claimed and it can lead to some pretty detrimental effects, not just for your workout but for your long-term health.

Immediate effects

The immediate impact of a high-stim pre-workout is pretty obvious. Your heart starts pounding, you feel the blood coursing through your veins; you’re more awake and more alert than you have ever been, and you’re ready to run a marathon or squat the world.

Caffeine is one of the most powerful and widely consumed central nervous system stimulants out there and the effects peak within about 30-60 minutes of consumption and can remain in your bloodstream for up to 9 hours.

So, while the “heart-pumping” effects may dissipate, the more subtle effects are still lingering.

For most people—depending on caffeine sensitivity—the immediate effects of caffeine consumption are pretty apparent, but when consumed in excess, it can cause some unpleasant and highly unwelcomed side effects that interfere with performance:

  • Heart palpitations
  • Nervousness
  • Jitters
  • Nausea
  • Anxiety
  • Increased blood pressure
  • Insomnia
  • Fatigue
  • Increased urination
  • Addiction

It’s a long list of immediate side effects that aren’t conducive to getting in a good workout. So, while you may be left wondering whether the higher caffeine pre is going to give you better results, chances are it’s not.

Long-Term Effects

Chronic excessive use of caffeine can be detrimental to overall health and can result in an increased risk of things like high blood pressure, nervous system damage, bone thinning due to calcium loss, and others.

However, two of the major long-term impacts of high caffeine intake are tolerance and withdrawal. Tolerance happens with chronic high caffeine consumption and refers to reduced responsiveness to the compound.

On the other hand, we have withdrawal. When someone has built up a tolerance to caffeine, reducing consumption or quitting cold turkey can result in some unpleasant “withdrawal” symptoms, including:

  • headache
  • fatigue or drowsiness
  • dysphoric mood
  • low mood or depression
  • irritability
  • difficulty concentrating
  • flu-like symptoms (nausea, vomiting, muscle pain, or stiffness) [10].

The effects typically appear about 12–16 hours after stopping intake and peak around 24-48 hours after 11.

Rather than getting yourself to a place where tolerance and withdrawal are a thing and begin to interfere with your performance, consuming moderate-dose caffeine is more ideal.

The Benefit Of Low And Moderate-Dose Caffeine

There’s a large body of research behind the beneficial effects of caffeine in low to moderate doses of 3-6mg/kg body weight, but there’s also evidence showing that more isn’t necessarily better with caffeine 12.

Aside from the nasty long and short-term side effects that come along with high doses, research indicates that higher doses of caffeine (>/= 9 mg/kg) do not result in further performance enhancement.

Studies also find that lower doses of caffeine (1–3 mg/kg of body mass) do not cause any significant physiological responses (RER, alteration of blood lactate, glucose, etc.) but still appear to deliver ergogenic effects 2.

That’s because they don’t alter the peripheral whole-body response to exercise yet still improve vigilance, alertness, mood, and cognitive processes both during and after exercise with little to no nasty side effects 13.

What studies show is that lower doses actually elicit greater effects on cognition and brain activation compared to moderate or higher doses (6-9mg/kg) because they’re still capable of inducing caffeine’s effect not the CNS 14.

The Best Pre-Workout Supplement To Boost Energy And Focus (Without The Downsides)

So, you want a pre-workout that isn’t loaded with caffeine but will still give you everything (and more) that traditional pre-workouts have to offer?

You may have been under the impression that it wasn’t possible, but it is.

Pre Lab Pro is the world’s smartest and most effective moderate-dose caffeine pre-workout supplement on the market. It delivers bigger and better results than any other pre-workout formula and is designed to push your body to its limits.

With 2x muscle-pumping nitric oxide (NO) turbocharge plus afterburn, it supports all-around athletics for optimal and peak performance.

With the addition of moderate-dose smart caffeine (80 mg), hydrating factors, and restorative essentials, Pre Lab Pro will power you through the longest and most intense training sessions with ease.

Here’s why you need it:

  • Enhanced athletic, nootropic, and thermogenic performance
  • Increases alpha brainwaves to balance caffeine energy with calm control and clarity
  • Helps reduce jitters, crashes, and other negative effects of caffeine overstimulation
  • Replenishes caffeine-depleted brain chemicals for daily use with less burnout
  • Promotes balanced physiological responses to caffeine-induced stress
  • Supports a healthier recovery and faster bounce-back after training

What you’re getting:

  • 1500mg RedNite® Beetroot Powder for healthier and improved improve neuromuscular performance, less fatigue, better muscle energy, healthy cardiovascular performance, and sharper cognitive function
  • 2200mg Setria® Performance Blend delivers a powerful and sustained nitric oxide boost for better strength, power, speed, and endurance, plus accelerated muscle growth and recovery
  • 80mg Natural caffeine supplies moderate-dose smart caffeine stacked with boosters and balancers for maximum benefit and minimal side effects
  • 400mg Ajipure® L-Tyrosine for supporting brain chemicals that drive athletic intensity and mental recovery, while sharpening focus under stress and replenishing neurotransmitters that are depleting by caffeine consumption and intense training
  • 160mg Suntheanine® for relaxed alertness, stable mood, and cognitive clarity, plus it enhances the effects of caffeine to promote calmer, cleaner stimulation

Final Thoughts

High dose caffeine has always been the buzz in the fitness world—no pun intended—but more and more research is supporting the role of moderate or low doses to provide equal, if not a better, effect on athletic performance.

Because caffeine overstimulation is easy to come by, you might get the exact opposite of what you wanted for your workout. Rather than treading water and walking the line between a stellar and poor training session, opt for a pre-workout that is guaranteed to get you results.

Pre Lab Pro does that. With moderate doses of caffeine, you’re guaranteed to take your performance to a level you’ve never experienced before without having to worry about the after-effects.


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