A wise woman once said, “Exercise gives you endorphins. Endorphins make you happy.” We trust Elle Woods—she is a lawyer, after all—but even the proven mood-boosting effect of a workout American Psychological Association “The Exercise Effect” View Source isn’t always enough to get you out of bed in the morning or off the couch after a long day of work.

Pre-workout supplements are marketed as the perfect pick-me-up to boost energy and exercise performance (and, in theory, motivation). Effects can last anywhere from 30 minutes to two hours after you take them. But depending on the active ingredients and the person, this timeframe can vary.

Here’s what to know about different pre-workout ingredients, what they do for you, and how long they provide you with the energy you need to kick your workout’s butt.

What Is Pre-Workout, Exactly?

Pre-workout is a dietary supplement some people take before exercising. It comes in various forms, ranging from pills and drinks to snacks and gummies. The most common form, however, is a powder that you mix with water.

Every pre-workout variety contains a unique combination of ingredients—usually a mix of caffeine, amino acids, creatine, and other nutrients But they all have the same goal, which is to increase your energy to get you pumped up before a gym sesh and boost performance once you’re in action. 

Different pre-workouts not only have unique ingredients, but they also vary in quality and quantity. Some have synthetic additives and high levels of sugar while others aim to just deliver the essentials. 

The ultimate question: Is pre-workout is necessary for optimal workout performance? Probably not. “I’ve been training for over 40 years and have never taken them, and I’ve had great results,” says to world champion powerlifter Robert Herbst. “All one needs before training is some carbs, a little protein, and some water. Anything else in a pre-workout is just artificial stimulation.”

How Long Can Pre-Workout Last In Your Body?

Whatever kind of pre-workout you take, it will pass through your body within 24 hours. However, everyone’s body metabolizes things differently, so there’s no precise way to know how long a pre-workout will last for you—that is, until you try it for yourself.

The best way to assess the lasting effects of a pre-workout supplement without taking it is to look at each ingredient individually. 

The half-lives (or the amount of time it takes for an ingredient to get to half of its original amount) of the most common pre-workout ingredients are:

• Caffeine: 1.5 to 9 hours
• Creatine: 3.85 hours
• Beta-Alanine: 3 hours
• BCAAs: 5 hours
• Citrulline: 60 minutes
• Taurine: 42 minutes to 1 hour 24 minutes
• L-Arginine: 30 minutes to 2 hours

The lasting effect of pre-workout also depends on other factors like:

• Your body type
• Serving size
• Your sensitivity to the ingredients
• The amount of each ingredient in your pre-workout
• Pre-existing health conditions
• How hard you work out

So, what does all of this information tell you? For one: pre-workout supplements are unpredictable. A safe way to test a pre-workout is to start with a small amount and see how it affects you. (Ideally not too close to bedtime so it doesn’t impact your sleep.)

Benefits and Risks of Pre-workout

There are both risks and benefits to taking pre-workout. But because every formula, person, and situation is different, there’s no way to predict how you’ll react. In fact, you may experience side effects one day and benefits another day. The risks and benefits listed below are possible but not guaranteed. 

Potential risks:

• Jitters, anxiety, heart palpitations, and inability to sleep from high caffeine intake
• Dependency if overused
• Gas, stomach discomfort, and diarrhea if they have high levels of sugar alcohols
• Water retention and bloating from creatine consumption
• Negative interactions with some medications

If you decide to pre-workout, it may be a good idea to avoid taking it every single time you exercise. “When you take pre-workout daily, it can start to interfere with your ability to get naturally energized and focused for your workout,” says Daniel Powers, MSc in Supplement Formulation and founder of The Botanical Institute. “Rather than using pre-workout powder daily, a better way is to use it only on days when you’re dragging. When you feel naturally energized and motivated, use that to fuel your workouts.”

Potential benefits:

• Improved energy and performance  
• Increased endurance 
• Increased blood flow and oxygen
• Enhanced recovery
• More lean body mass

To reduce pre-workout side effects, stay hydrated and eat within two hours of your workout. “The body’s first fuel source is carbohydrates,” says Lisa Richards, CNC. “It’s important to fuel your body with high-quality carbs from whole grain sources, not refined carbohydrates that are highly inflammatory and stored quickly.” Adding some protein before you exercise—such as toast and eggs alongside your pre-workout—may help slow down digestion and minimize side effects. 

Pre-Workout Ingredients You Should Know 

Ignorance isn’t bliss with pre-workouts. It’s important to know what ingredients you’re consuming. But the power is in your hands. If you can make sense of standalone ingredients, you can decide which supplement is right for you.

Caffeine

What it may do: Boost energy and sharpen focus.

Caffeine, a stimulant often found in coffee and tea, is the most common ingredient in pre-workout supplements because it provides a short-term surge of energy. Caffeine can improve exercise performance Journal of the International Society of Sports Nutrition “International society of sports nutrition position stand: caffeine and exercise performance” View Source when consumed in doses of 1.4–2.7 mg/lb of body mass, according to the Journal of the International Society of Sports Nutrition. Very high doses of caffeine have an increased risk of side effects, such as dehydration, restlessness, and insomnia. Caffeine is also a gastric irritant, so it may upset your stomach.

Use the following formula to determine your daily dose: 

(Weight in pounds) x 2 = Average daily caffeine in mg

A cup of coffee has roughly 95 mg of caffeine, while pre-workouts can range in caffeine content from 150mg to 300mg. People shouldn’t have more than 400 mg of caffeine Food and Drug Administration “How Much Caffeine is Too Much?” View Source (about four cups of coffee) a day, according to the FDA. 

Pre-workout to try: 

Optimum Nutrition’s Amino Energy Pre-Workout is a popular pre-workout that contains caffeine. However, it doesn’t have too much caffeine—about 100 mg per serving, which is less than most other brands—plus other amino acids. “Optimum nutrition is one of the biggest names in supplements, meaning it’s carried almost everywhere,” says Kyle Risley, Mass-Lift Powerlifter and CEO of LiftVault. “Even better, its formula has plenty of BCAAs mixed with caffeine, so it does the job of two supplements in one.”

Prefer to opt out of caffeine? Legion Pulse Caffeine-Free Pre-Workout is a good option.

Creatine

What it may do: Increase performance and enhance recovery.

Creatine Mayo Clinic “Creatine” View Source is an amino acid that the body produces naturally and stores in the muscles and brain. It can also be found in meat and seafood. Its synthetic version is a popular additive to pre-workout supplements because it can increase performance and enhance recovery. 

Natural creatine levels vary based on things like your meat intake, level of exercise, muscle mass, and testosterone levels. While you already have creatine in your body, pre-workout supplements have higher doses that can heighten its benefits.

You produce 1 to 2 grams of creatine per day, and if you’re a regular meat-eater, you eat 1 to 2 grams per day, according to Healthline. You can take a higher dose of creatine for a short period, but you should then revert to a lower dose. Two common dosages for “loading,” or when you increase creatine consumption to maximize muscle storage, are:

1.  20 grams per day for seven days followed by 10 grams per day for seven days
2.  20 grams per day for 10 days followed by 4 grams per day for 20 days

For maintenance, you can take 3-5 grams per day.

There are conflicting studies that discuss the interaction between caffeine and creatine. Some studies have shown that caffeine can make creatine less effective Human Kinetics Journal “Interaction Between Caffeine and Creatine When Used as Concurrent Ergogenic Supplements: A Systematic Review” View Source . Others showed no issues when caffeine and creatine were taken together European Journal of Applied Physiology “Effect of caffeine ingestion after creatine supplementation on intermittent high-intensity sprint performance” View Source . It’s commonly believed that creatine can contribute to kidney issues, but a study done on patients with type 2 diabetes found it did not interfere with kidney function European Journal of Applied Physiology “Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial” View Source . However, more study is needed—check with your doctor before taking creatine if you’re unsure.   

Pre-workout to try:

Khushali Shah, co-founder of the blog Healthy and Khush, recommends C4 Original Pre-Workout. It contains 1 gram of creatine nitrate, plus other ingredients like beta-alanine and caffeine. “It has an optimal dosage of creatine and caffeine,” she says.

Beta-Alanine

What it may do: Prevent acid buildup and increase endurance.

If you take a  pre-workout powder and start to feel your hands tingle or itch, don’t worry. That’s just the beta-alanine kicking in. This side effect, called paresthesia National Institute of Neurological Disorders and Stroke “Paresthesia Information Page” View Source , isn’t harmful and should go away quickly. The effect can also happen with niacin, another common pre-workout ingredient. (It’s often referred to as “niacin flush.”)

Beta-alanine is an amino acid found in many pre-workout supplements. It prevents acid buildup in your muscles and allows them to work harder during a workout. It also increases your natural levels of carnosine Antioxidants “Carnosine, Small but Mighty—Prospect of Use as Functional Ingredient for Functional Food Formulation” View Source , which is an organic compound with anti-inflammatory and antioxidant properties. 

Evidence shows that using creatine and beta-alanine together can increase lean muscle mass and aid in body fat reduction Human Kinetics Journal “Effect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletes” View Source . You can get beta-alanine from foods like red meat, fish, and poultry, but if you’re supplementing with beta-alanine, shoot for 2–5 grams per day.

One study found that beta-alanine supplementation induced taurine depletion Experimental Eye Research “β-alanine supplementation induces taurine depletion and causes alterations of the retinal nerve fiber layer and axonal transport by retinal ganglion cells” View Source and that this depletion could have a negative effect on cells and nerves related to eyesight. This is the first study to report these findings and more research is likely needed.

Does pre-workout make you feel tingly? If you experience a tingling, pins and needles, prickly, or itchy sensation after taking pre-workout, you may just be more sensitive to Beta-Alanine. The tingling sensation is known as paresthesia PubMed Central “International society of sports nutrition position stand: Beta-Alanine” View Source . While it sounds scary, paresthesia is a normal effect of Beta-Alanine. As for how long the pre-workout tingle lasts, it varies, but you can expect it to start about fifteen minutes after you take it and last anywhere from a few minutes to an hour. To reduce the tingling sensation, consider using divided lower doses (1.6 g) or a sustained-release formula PubMed Central “International society of sports nutrition position stand: Beta-Alanine” View Source .

Pre-workout to try:

Looking for a pre-workout with beta-alanine? Consider Natural Pre-Workout by Naked Nutrition, recommended by Tom Papas, international basketball player for AO Mykonos. It contains 2 grams of beta-alanine, plus other ingredients like creatine and caffeine.

Branched-chain amino acids (BCAAs)

What it may do: Increase muscle mass and reduce muscle damage. 

Branched-chain amino acids—BCAAs for short—include the essential nutrients: leucine, isoleucine, and valine. (Basically, amino acids that stimulate muscle production and may reduce damage) Pre-workout supplements often include BCAAs because some studies have shown that they increase muscle mass and can reduce muscle damage Nutrients “Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review” View Source . 

Disclaimer: BCAAs only showed effectiveness in clinical studies when muscle damage was low to moderate. So, if you’re really pumping iron, this may not be the ingredient for you. If you decide to take BCAAs, the recommended daily dose is 91 mg/lb before working out. To see improvement in muscle mass and recovery, you’ll need to take BCAAs for over 10 days.

Use the following formula to determine your daily dose: 

(Weight in pounds) x 91 = Daily BCAAs in mg

For example, if you weigh 130 lbs, the recommended daily dose of BCAAs would be 11,830mg.

Pre-workout to try:

Alicia Parker, certified personal trainer strength and conditioning specialist, recommends KONO Pre-Workout by Kono Nutrition. It contains 5 grams of BCAAs, plus other ingredients like citrulline malate and caffeine.

Citrulline

What it may do: Increase blood flow and reduce muscle soreness.

Citrulline is another amino acid that your body produces on its own, but higher levels may benefit workout performance. Citrulline increases vasodilation,or the widening of blood vessels. When your blood vessels widen, blood flow increases and you receive more oxygen, which helps you work out longer and harder. 

In one study, participants performed 53% more upper body repetitions after taking citrulline malate Journal of Strength and Conditioning Research “Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness” View Source when compared to those who took a placebo. Participants also had 40% less muscle soreness. There aren’t any widely reported citrulline side effects, but it may impact the way other drugs work for you, such as nitrates for heart disease and ED medication. It may also cause stomach discomfort. Talk with your doctor before taking a citrulline supplement if you take any of these medications.

Citrulline comes in two forms: L–citrulline and citrulline malate. The recommended daily dose is 3–6 grams per day of L-citrulline or approximately 8 grams of citrulline malate daily, according to Healthline.

Pre-workout to try: 

To get your citrulline fix, look to Legion Pulse Caffeine-Free Pre-Workout. It contains 8 grams of citrulline malate, plus other ingredients like beta-alanine, and is a favorite of David Brendan, RDN and certified fitness trainer. “What it lacks in caffeine, it more than makes up for other key performance ingredients,” he says.

L-Arginine

What it may do: Increase blood flow, rebuild muscle tissue, and build protein.

L-arginine is—wait for it—yep, another amino acid. This supplement may have a mixture of benefits resembling the others listed above. It helps the body build protein, rebuild tissue, and functions as a vasodilator. 

Like the other amino acids, you can get L-arginine from a high-protein diet, but food alone may not give you enough to see improvements in your workouts.  L-arginine Mayo Clinic “L-arginine” View Source may cause headaches, nausea, and worsening of asthma and/or allergy symptoms. You also shouldn’t take it if you’ve recently had a heart attack, as this may increase the risk of death.

Studies on the effectiveness of L-arginine vary, but one promising study found that male soccer players experienced increased sport performance when taking two grams of L-arginine daily for 45 days European Journal of Clinical Nutrition “The effect of l-arginine supplementation on body composition and performance in male athletes: a double-blinded randomized clinical trial” View Source . Another study, however, found that L-arginine showed no meaningful difference from the placebo The Journal of Sports Medicine and Physical Fitness “Acute supplementation of L-arginine affects neither strength performance nor nitric oxide production” View Source in improving strength performance. 

Highly-rated pre-workout:

Natural Pre-Workout by Naked Nutrition is also a great option if you’re looking for a pre-workout with l-arginine. It contains 1 gram of l-arginine, plus other ingredients like creatine and beta-alanine, and is recommended by Tom Papas, international basketball player for AO Mykonos.

Taurine

What it may do: Decrease muscle fatigue and increase endurance.

Taurine is an amino sulfonic acid—which differs from an amino acid, in case you were wondering. Most amino acids are non-essential and are used to build proteins in the body, but taurine differs in that it’s a conditionally essential amino acid. It becomes essential when you’re sick or stressed, and our bodies naturally make it from other amino acids. You can also consume taurine through dairy products, meat, poultry, fish, and eggs. (Noticing a pattern?)

Pre-workout supplements contain taurine because it may reduce lactate buildup—which in turn decreases muscle fatigue. One study also found that combining caffeine with taurine over a two-week period enhanced endurance International Journal of Sports Medicine “Caffeine and taurine enhance endurance performance” View Source .

An average diet provides about 40–400 mg of taurine per day, but supplement doses commonly range from 500–2,000 mg per day.

Alright, science class dismissed! Now that you’ve enhanced your knowledge of pre-workout ingredients, you can decipher nutrition labels and choose the best supplement for you.  

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Sourcing:

• Pre-workout supplements containing caffeine have been demonstrated to enhance aerobic performance. International society of sports nutrition position stand: caffeine and exercise performance (January 2021)
• Pre-workout supplements are meant to give you energy for when you exercise. Health Benefits of Pre-Workout Supplements (June 2021)
• This article explains whether pre-workout supplements are healthy. Pre-Workout Supplements: Ingredients, Precautions, and More (December 2021)
• We explain common ingredients found in pre-workout supplements, and the best pre-workout supplements to buy now. What Are Pre-Workout Supplements? A Complete Guide | The Manual (February 2021)
• Your body stores creatine as phosphocreatine primarily in your muscles, where it’s used for energy.  Creatine – Mayo Clinic (February 2021)
• Learn about creatine supplementation including if it’s safe for seniors to use, dosage, and if there are any anti-aging benefits to it. Is Creatine Safe for Older Adults? (March 2021)
• Creatine loading can result in a significant gain in body weight due to an increase in both muscle mass and water intake into your muscles. Can You Take Too Much Creatine? Side Effects and Dosage (April 2019)
•  Carnosine is a dipeptide synthesized in the body from β-alanine and L-histidine. Carnosine, Small but Mighty—Prospect of Use as Functional Ingredient for Functional Food Formulation (July 2021)
• Beta-alanine is an amino acid that is often taken as a sports supplement. It can improve exercise performance and boost overall health. Beta-Alanine — A Beginner’s Guide (December 2018)
•  Creatine plus beta-alanine supplementation appeared to have the greatest effect on lean tissue accruement and body fat composition. Effect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletes (August 2006)
• BCAAs supplementation can be efficacious on outcomes of exercise-induced muscle damage. Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review (September 2017)
• BCAAs supplements often claim to improve muscle gains and exercise performance. BCAA supplements: Helpful or hype? Experts sound in on the popular fitness product | CBC Life (October 2019)
•  BCAA supplements conveniently provide muscle-supportive nutrients. However, scientists question whether these supplements offer an advantage When Should You Take BCAAs? (June 2017)
• Citrulline is an amino acid that’s becoming popular as a supplement for health and exercise performance. Should You Take Citrulline Supplements? (April 2017)
• Vasodilation is the widening of your blood vessels. Vasodilation: Your Blood Vessels Opening (November 2018)
• The use of caffeine and taurine over a 2 week period enhanced endurance performance. Caffeine and taurine enhance endurance performance (July 2009)
• L-arginine is an amino acid that helps the body to build proteins. Athletes and others seek out ways to boost their L-arginine intake. L-arginine: Potential benefits, side effects, and risks (July 2017)
• Despite the potential positive effects of arginine supplementation on exercise metabolism, it is still premature to recommend dietary supplements containing arginine. Pre-exercise Arginine Supplementation Increases Time to Exhaustion in Elite Male Wrestlers (August 2014)
• Many people take pre-workout supplements to boost their performance at the gym. How Long Does a Pre-Workout Last? All You Need to Know (July 2021)
• The average biological half-life of creatinine in normal male adults between 20 to 39 years old is 3.85 hours. Pharmacokinetics of creatinine in man and its implications in the monitoring of renal function and in dosage regimen modifications in patients with renal insufficiency (May-June 1975).
• The half-life of citrulline was reported to be approximately 60 minutes. Therapeutic potential of citrulline as an arginine supplement: a clinical pharmacology review. (June 2020).
• Oral administration of taurine in healthy individuals gave a plasma elimination half-life that ranged from 0.7-1.4 hours. Taurine: Uses, Interactions, Mechanism of Action | DrugBank Online. (February 2021)
•  Its half-life has been reported to be 25 min, while return to the baseline concentrations occurs 3 h post-ingestion. β-Alanine supplementation and military performance. (July 2015)
• Your heart needs exercise — and what you eat before, during and after physical activity can affect your performance and how you feel. Fuel Your Fitness | Johns Hopkins Medicine
• While pre-workout supplements can provide some benefits, they may also cause side effects, such as nausea and heart abnormalities. Potential pre-workout side effects and how to reduce them (October 2021)
• Several ingredients in pre-workout formulas may cause digestive upset. 5 Side Effects of Pre-Workout Supplements (July 2019)
• International society of sports nutrition position stand: Beta-Alanine (J Int Soc Sports Nutr.)
• WHY DOES BETA-ALANINE MAKE YOU ITCH? CAN YOU STOP THE TINGLE? (Ladder)