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What Is Stim-Free Pre-Workout & How Does It Work?

Michael Garrico
Published by Michael Garrico
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: January 25, 2022

Most pre-workouts have one common problem. They give you a sudden rush of energy, only to leave you feeling worn out just moments later.

That problem can be solved with stim-free pre-workouts.

These supplements contain zero stimulants but allegedly still have the benefits of regular pre-workouts.

I wanted to know whether that was myth or truth. So, I’ve partnered with a dietitian to do some research and find out.

Here’s what we’ve discovered.

Quick Summary

  • Stim-free pre-workout refers to supplements that don't contain any stimulants, such as caffeine or guarana.
  • Stimulant-free pre-workouts work by increasing nitric oxide (NO) levels that speed up blood flow and visibly increase muscles.
  • Choose stim-free pre-workouts if you’re experiencing stimulant side effects.

What Is Stim-Free Pre-Workout, Exactly?

preworkout supplements

Stim-free pre-workout is a stimulant-free supplement that should be taken before workouts.

It’s supposed to give you more energy and focus while you exercise and help you achieve visible results faster [1].

That’s what all pre-workout supplements are intended for. However, most of them rely on stimulants to equip you with energy.

Stim-free pre-workouts don’t.

Instead, most of them work by increasing your nitric oxide (NO) levels. Nitric oxide then further increases the pump of your muscles.

In other words, it makes your muscles look visibly larger [2].

Some people take stim-free pre-workouts on their own. Others combine them with regular pre-workouts that contain some stimulants, such as caffeine.

Let’s discuss the differences between the two in more depth.

Stim Vs. Non-Stim Pre-Workouts

stack of coffee beans and powder

Pre-workouts usually contain stimulants like [3]:

  • Caffeine
  • Guarana
  • Yohimbine

These stimulants may not be the most healthy for you, especially when taken in higher doses [4, 5].

But most pre-workout supplements contain hefty amounts of stimulants. The reason is that the stimulants get you that spike in energy you feel after taking pre-workout.

So, the effects you feel after taking pre-workouts are actually caused by stimulants. Without them, pre-workouts wouldn’t be as effective.

Almost every stim pre-workout contains some amount of caffeine.

You probably know how caffeine works if you’ve ever had a cup of coffee. Caffeine helps you fight sleepiness and boosts your energy levels.

The problem is that too much caffeine may lead to palpitations, heart attacks, and other cardiovascular problems, especially if you already have some heart problems [6]. You may also experience jitters when the caffeine wears out [7].

But caffeine isn’t the only ingredient that can increase your energy. There are other, healthier options to choose from.

Related: Best Caffeine Free Pre-Workout

For example, stim-free pre-workout contains ingredients such as [8]:

  • Betaine
  • Beta-alanine
  • Creatine
  • Taurine
  • TeaCrine
  • Nitrosigine

Is Non-Stim Pre-Workout Effective?

woman holding up a preworkout powder supplement in gym clothes

Yes, non-stimulant pre-workout is effective. But it works in a way that’s different from supplements you’re probably used to.

Non-stim pre-workout supplies your body with the ingredients it needs to produce nitric oxide [9]:

“Nitric oxide is a gas that the body produces, and it helps with blood flow. Nitric oxide supplements try to increase the amount of nitric oxide in your blood, which might help increase blood flow to working muscles and help reduce time to fatigue during a workout.” -Natalie Rizzo, M.S., R.D.

In a nutshell, nitric oxide is a gas that opens up your blood vessels and speeds up your blood flow.

In doing so, it allows important nutrients to get to the muscles you’re training faster. And the more quickly your muscles get the nutrients they need, the faster they’ll grow.

Think of it as supplying your muscles with food. Just like you need food to grow — as your mom probably told you numerous times — so do your muscles.

Additionally, nitric oxide will also decrease muscle soreness and help the muscles recover faster [10].

Stim-Free Pre-Workouts — Benefits

female in gym clothes showing her bicpes

Non-stimulant pre-workout has pretty much the same benefits as regular, stimulant pre-workout [11]:

  • It increases energy production
  • It increases focus
  • It enhances blood flow

But there’s also one added benefit — the fact that stimulant-free pre-workouts don’t lead to jitters, palpitations, or other possible side effects of stimulant pre-workouts.

What’s The Right Option For You?

Pre-workouts with stimulants aren’t necessarily bad. The key is taking them in moderation and following the instructions for use.

Still, you might enjoy non-stim pre-workouts more if you are sensitive to stimulants or simply prefer the pump over an energy boost. In that case, feel free to go for non-stim supplements.

I’d also recommend them if you’re trying to cut caffeine in general.

FAQs

Can Beginners Use Pre-workout?

Yes, beginners can use pre-workout - it doesn’t matter if you’re a beginner or a pro. If you’re looking to boost your energy levels and improve endurance, pre-workouts are the way to go.

Can I Take Pre-workout on an Empty Stomach?

You can take most pre-workouts on an empty stomach. Many pre-workouts have been formulated in a way that won’t cause any digestive issues when taken without meals [12]. However, it’s always best to check what the instructions on your supplement say.

Should You Take Pre-workout Under 18?

You can take pre-workout under 18, although that doesn’t mean you should. So far, the studies haven’t found conclusive evidence that would suggest that you either should or shouldn’t take supplements under 18 [13].

Should You Try Stimulant-Free Pre-Workout?

With stimulant-free pre-workouts, you should still be able to endure more intense training, although you won’t get an energy boost from caffeine.

That’s why I suggest you try them, especially if you’re not responding well to supplements that contain stimulants.

You can start by combining stim-free pre-workouts with regular ones.

Try to compare the effects of each supplement and assess which option is better for you. You won’t know for sure until you’ve tried both.


References:

  1. https://www.healthline.com/nutrition/pre-workout-supplements 
  2. https://www.mdriveformen.com/blogs/the-driven/5-ways-nitric-oxide-can-improve-muscle-growth-and-your-sex-life
  3. https://www.bodybuilding.com/content/the-complete-guide-to-pre-workout-supplements.html 
  4. https://www.webmd.com/vitamins/ai/ingredientmono-979/caffeine
  5. https://www.metrocardiovascular.com/blog/how-caffeine-can-lead-to-palpitations
  6. https://www.rxlist.com/consumer_yohimbine_aphrodyne_yocon/drugs-condition.htm 
  7. https://spoonuniversity.com/how-to/how-to-calm-coffee-jitters-after-consuming-too-much-caffeine
  8. https://endurelite.com/blogs/free-nutrition-supplement-and-training-articles-for-runners-and-cyclists/stim-free-pre-workouts-how-to-choose-the-right-one
  9. https://www.menshealth.com/health/a19717792/nitric-oxide-supplements/ 
  10. https://www.mdriveformen.com/blogs/the-driven/5-ways-nitric-oxide-can-improve-muscle-growth-and-your-sex-life
  11. https://www.prosupps.com/blogs/articles/is-stimulant-or-non-stimulant-pre-workout-better 
  12. https://totalshape.com/supplements/pre-workout-on-empty-stomach/ 
  13. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/is-it-safe-for-my-kid-to-take-supplements

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