With the growing popularity of pre-workout supplements, a common question arises: how long does pre-workout last after you take it?

Knowing how long a pre-workout lasts is important for timing your intake correctly and ensuring you get the most out of your training while its effects peak.

It’s also important for safety reasons.

Understanding the duration of a pre-workout’s effects helps avoid side effects like disrupted sleep or excessive post-workout fatigue. By being aware of how long the supplement works, you can avoid taking it too close to bedtime and ensure you’re not overlapping doses.

In this article, you’ll learn what pre-workout supplements are, what they typically contain, how long pre-workout lasts, the benefits and common side effects associated with taking pre-workout, the best pre-workout, and more.

What Are Pre-Workout Supplements?

A pre-workout supplement, or “pre-workout” for short, is a sports nutrition supplement taken before training to enhance energy levels and athletic performance.

Typically, a pre-workout supplement is a powder that you mix with water and drink. 

Find the Perfect Supplements for You in Just 60 Seconds

You don't need supplements to build muscle, lose fat, and get healthy. But the right ones can help. Take this quiz to learn which ones are best for you.

Take the Quiz

Common Pre-Workout Ingredients

There are thousands of pre-workouts on the market, each boasting a unique blend of ingredients.

Despite this diversity, some ingredients are more commonplace than others, whether because studies show they’re effective or because famous athletes or bodybuilders endorse them.

Some of the most popular ingredients and their benefits are:

  • Caffeine: Caffeine increases alertness and reduces perceived effort and fatigue. The dehydrated and powdered form of caffeine, caffeine anhydrous, is perhaps the most common ingredient in pre-workout formulas.
  • L-Citrulline: L-citrulline increases nitric oxide production in the body, enhancing blood flow and boosting oxygen and nutrient delivery to muscles, which can improve performance, reduce fatigue, and accelerate recovery.
  • Beta-Alanine: Beta-alanine is an amino acid that increases muscle concentrations of carnosine. It helps diminish the downsides of acid buildup in your muscles, boosting athletic performance during high-intensity exercise.
  • L-Theanine: L-theanine can help smooth out caffeine’s stimulatory effects, leading to a more focused and less jittery energy boost.
  • Betaine: Betaine helps improve muscle endurance and increases strength. It may also play a role in muscle protein synthesis.
  • Alpha-GPC: Alpha-GPC enhances cognitive function and increases power output, making it beneficial for activities that require both mental and physical exertion. 
  • Creatine: Creatine helps you produce more ATP, a key energy source for heavy lifting and high-intensity exercise. While taking creatine before training is unnecessary, many supplement manufacturers include creatine in their pre-workout supplement formulations. 
  • L-Tyrosine: L-tyrosine is a precursor to neurotransmitters like dopamine and adrenaline, helping to increase focus and alertness during workouts.
  • Taurine: Taurine may reduce muscle damage and fatigue and support metabolic processes and energy production.

How Long Does Pre-Workout Last?

How long a pre-workout lasts depends on each active ingredient’s half-life.

An ingredient’s half-life refers to the time it takes for the body to eliminate half of the substance or how long it takes for the substance to lose half of its pharmacologic, physiologic, or radiologic activity.

In the context of nutrition and supplements, this concept is often applied to understand how long a substance remains active or effective in the body.

The half-lives of the above ingredients are as follows:

  • Caffeine: Caffeine’s half-life is approximately 5 hours, though this varies widely depending on individual factors such as metabolism and tolerance.
  • L-Citrulline: The half-life of l-citrulline increases with the dose, ranging from ~40-to-75 minutes for doses of 2-to-15 grams.
  • Beta-Alanine: Beta-alanine’s half-life is approximately 25 minutes. However, as its benefits come from long-term, cumulative use, its half-life has little bearing on how long its effects last.
  • L-Theanine: L-theanine’s half-life is typically just over an hour. 
  • Betaine: Betaine has a half-life of around 60 minutes, though this may extend with continued use. 
  • Alpha-GPC: Studies show that after taking alpha-GPC, choline levels increase for up to 2 hours.
  • Creatine: While creatine monohydrate has a half-life of about 90 minutes, its effectiveness extends far beyond this timeframe, provided you use it daily for an extended period.
  • L-Tyrosine: L-tyrosince’s half-life is 2-to-3 hours.
  • Taurine: Taurine’s half-life is 1-to-3 hours.

In other words, most common pre-workout ingredients are effective soon after you take them and remain beneficial for 1-to-2 hours. 

Therefore, to reap its performance-enhancing effects, it’s sensible to take pre-workout between 15 and 30 minutes before you train and limit your workouts to no longer than 90 minutes. 

Find the Best Diet for You in Just 60 Seconds

How many calories should you eat? What about "macros?" What foods should you eat? Take our 60-second quiz to get science-based answers to these questions and more.

Take the Quiz

Benefits of Taking Pre-Workout

The main benefits of pre-workout are:

  • Enhanced athletic performance: Ingredients such as caffeine, l-citrulline, beta-alanine, betaine, and creatine boost strength, enhance endurance, and reduce fatigue, which helps you train harder for longer and may increase muscle and strength gain over time. 
  • Improved focus: Compounds like caffeine, l-theanine, and l-tyrosine boost focus, alertness, and mood.
  • Faster recovery: Creatine, l-citrulline, and taurine can help mitigate post-workout soreness and accelerate recovery.

Common Pre-Workout Side Effects

While pre-workout supplements offer numerous benefits, they can also have potential side effects, especially when not used as directed. Being aware of these can help you make informed decisions about their use.

Some common side effects include:

  • Jitters and Anxiety: Due to the high caffeine content in many pre-workout formulas, some individuals may experience jitters, anxiety, or restlessness. This is particularly true for those sensitive to stimulants.
  • Digestive Issues: Ingredients in pre-workouts, like certain amino acids or artificial sweeteners, may cause digestive discomfort for some users. This can manifest as stomach upset, bloating, or diarrhea.
  • Increased Heart Rate and Blood Pressure: Stimulants like caffeine can cause a temporary increase in heart rate and blood pressure, which may be concerning for those with heart conditions or hypertension.
  • Skin Tingles: Beta-alanine can cause a harmless but sometimes uncomfortable tingling sensation on the skin, known as paresthesia.
  • Insomnia: Taking pre-workout supplements too close to bedtime, especially those with high caffeine content, can interfere with your sleep. If you like to train late in the day and want to prevent pre-workout from interfering with your sleep, opt for a “stim-free” pre-workout. 
  • Dependency: There is a potential for developing a reliance on pre-workout supplements for exercise performance, which can lead to overuse or misuse.

What’s the Best Pre-Workout?

If you want a 100% naturally flavored and sweetened pre-workout supplement containing clinically effective doses of 6 performance-boosting ingredients like caffeine, l-citrulline, and beta-alanine, try Legion’s pre-workout powder, Pulse.

Or, if you’d prefer a 100% natural and stimulant-free pre-workout drink that boosts strength and stamina while reducing fatigue, try stim-free Pulse. 

(If you’re uncertain whether Pulse suits your needs and budget, take the Legion Supplement Finder Quiz to learn what supplements are right for you. Click here to check it out.)

Scientific References +