Benefits of Pre-Workout | What Is It? When To Take it?

Feel like you’re lagging when it comes to your workouts? Or, maybe you’re not even making it into the gym in the first place. If this is you, then it might be time to pick up a pre-workout. This supplement usually contains multiple ingredients to enhance your gym performance, so does it work? If so, how? Here’s the answers to all your pre-workout questions…

In this article, you’ll find:

man on cross trainer drinking supplement

What is Pre-Workout?

A pre-workout supplement is mix of different ingredients designed to help you get the best out of a training session.1

Ingredients tend to include those that have been shown to benefit exercise performance in some way. So, the idea is that taking the supplements together can help increase their benefit.1

The typical ingredients used in pre workout include caffeine, beta alanine, amino acids, nitrates and creatine.1

Due to the complex nature in how supplements work in the body, the evidence is unclear as to how well these ingredients work when put together. There is a currently a lack of evidence to demonstrate that taking a pre-workout is better than taking an individual supplement in isolation, however, taking them all in one supplement is far more convenient than taking them all separately.

Caffeine and Pre-Workout

Caffeine tends to the main ingredient used in a pre-workout and is responsible for most of the short term benefits.1 Caffeine is rapidly absorbed in the body, so if taken 60 minutes prior to an exercise session it will have reached peak levels in the bloodstream by the time you begin.2

There may be a number of potential ways in which caffeine enhances performance in the gym, however, it’s believed the most relevant mechanism of action is due to its effect on the central nervous system.2 When taken in isolation and in doses of 3-6g/kg of bodyweight, caffeine has been shown to improve endurance, power and resistance exercise.2

woman drinking supplement

Other Pre-Workout Supplements

Beta alanine is common ingredient used in pre workout and is responsible for face and skin tingling — a perfectly harmless side effect. 2-4g a day for a minimum of 2 weeks has been shown to increase your body’s production of carnosine.3

Carnosine is an important buffering agent during high intensity exercise by stopping your muscles from becoming overly acidic, which can lead to fatigue. Evidence has shown that beta alanine supplementation can improve muscular endurance and has improved the amount of reps performed in sets of bench press and back squat when supplemented for a period of 10 weeks.4

Creatine Pre-Workout

Creatine is one of the most heavily-researched sports nutrition supplements on the market and its benefits on improving strength and increasing lean body mass are well established.5

Creatine works by increasing the amount of phosphocreatine in your body, which is the main fuel source used during high-intensity exercise, such as resistance training.

Creatine can be loaded so that the performance effects happen quicker. However, in the dosage used in most pre workouts, it will take approximately 28 days to see much of a performance enhancement, so if you want to reap the benefits faster, then try a creatine supplement too.5

Nitric Oxide Pre-Workout

Nitric oxide is a signaling molecule which increases blood flow to your muscles during exercise. The strongest evidence to support its use for improving exercise performance is in its capacity to increase exercise tolerance.6

For example, it’s been shown that nitrate supplementation can help reduce the amount of phosphocreatine used during high-intensity exercise which may improve resistance to fatigue.7

Nitrates have been shown to improve both endurance and high-intensity exercise performance when supplemented in doses of 300mg.1


cyclist drinking supplement

Pre-Workout Benefits

Acute (same day)

The evidence suggests that a caffeine containing pre workout can enable you to retain your strength throughout a training session. Additionally, numerous studies have that a pre workout supplement has allowed people to perform more reps to failure during resistance exercise.1

A pre workout supplement may also benefit those training for an endurance event, as time to exhaustion has been improved by 12.5%. However, the research supporting pre-workouts and improved endurance performance is inconclusive with more studies needed.1

Long term (longer than 10 days)

When taking a pre-workout regularly alongside a resistance training program, evidence suggests that a pre-workout may help you make greater strength gains. This was demonstrated in a study that showed that a one rep max (the maximum weight you can lift for 1 repetition) in the bench press was increased more in those supplementing with a pre-workout compared to those who didn’t.8

Studies have shown that body composition has been improved with long term use of a pre-workout, with increases in lean body mass. However, due to the study designs, it’s hard to say whether improvements were due to the pre-workout or the levels of protein and creatine intake.1

When to Take Pre-Workout

The best time to take a pre-workout would be approximately 60 minutes prior to your training as this will ensure that the caffeine levels in your blood stream will have peaked.2

In order to the most of all the ingredients in a pre-workout, it would be best to take a pre-workout on a regularly basis for a period of weeks.1

With the time it takes to load both creatine and beta alanine in the doses included a pre-workout, you would need to take it for approximately four weeks.3,4

Pre-Workout Side Effects

The main side effect associated with a pre-workout is tingling of the skin due to the beta alanine content.4 With high doses of caffeine and creatine, a number of gastrointestinal issues have also been reported.2,5

When using any supplement for the first time, there may be some sort of adverse reaction. However, currently the evidence suggests that taking a pre-workout on a short term basis is relatively safe.1

There are currently very few studies looking into the safety of supplementation for periods longer than 8 weeks, so caution is advised if you’re planning on supplementing for longer than that.

Take Home Message

A pre-workout supplement may help you get more out of your training session by increasing force production and muscular endurance.

How much of an improvement in performance you see will be down to the combination of ingredients or whether it’s a single ingredient, so it’s hard to exactly predict the results.

The best time to take a pre-workout would be 60 minutes prior to a training session to allow the caffeine to take full effect.

Long term supplementation has shown encouraging results, but the specific mechanism of action is hard to pinpoint. As with any supplement there may be side effects. However, the most commonly reported are tingling of the skin and gastrointestinal issues.

If you need a boost to get through your workouts, or take them to the next level, then give pre-workout a go.

Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you’re concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.


  1. Harty, P., Zabriskie, H., Erickson, J., Molling, P., Kerksick, C. and Jagim, A. (2018). Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review. Journal of the International Society of Sports Nutrition, 15(1).
  2. Goldstein, E., Ziegenfuss, T., Kalman, D., Kreider, R., Campbell, B., Wilborn, C., Taylor, L., Willoughby, D., Stout, J., Graves, B., Wildman, R., Ivy, J., Spano, M., Smith, A. and Antonio, J. (2010). International society of sports nutrition position stand: caffeine and performance. Journal of the International Society of Sports Nutrition, 7(1), p.5.


  1. Trexler, E., Smith-Ryan, A., Stout, J., Hoffman, J., Wilborn, C., Sale, C., Kreider, R., Jäger, R., Earnest, C., Bannock, L., Campbell, B., Kalman, D., Ziegenfuss, T. and Antonio, J. (2015). International society of sports nutrition position stand: Beta-Alanine. Journal of the International Society of Sports Nutrition, 12(1).
  2. Hoffman, J., Ratamess, N., Kang, J., Mangine, G., Faigenbaum, A. and Stout, J. (2006). Effect of Creatine and ß-Alanine Supplementation on Performance and Endocrine Responses in Strength/Power Athletes. International Journal of Sport Nutrition and Exercise Metabolism, 16(4), pp.430-446.
  3. Buford, T., Kreider, R., Stout, J., Greenwood, M., Campbell, B., Spano, M., Ziegenfuss, T., Lopez, H., Landis, J. and Antonio, J. (2007). International Society of Sports Nutrition position stand: creatine supplementation and exercise. Journal of the International Society of Sports Nutrition, 4(1), p.6.
  4. Jones, A. (2014). Dietary Nitrate Supplementation and Exercise Performance. Sports Medicine, 44(S1), pp.35-45.
  5. Bailey, S., Fulford, J., Vanhatalo, A., Winyard, P., Blackwell, J., DiMenna, F., Wilkerson, D., Benjamin, N. and Jones, A. (2010). Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. Journal of Applied Physiology, 109(1), pp.135-148.
  6. Schmitz SM, Hofheins JE, Lemieux R. Nine weeks of supplementation with a multi-nutrient product augments gains in lean mass, strength, and muscular performance in resistance trained men. J Int Soc Sports Nutr. 2010;7:40.

Claire Muszalski

Claire Muszalski

Registered Dietitian

Claire is a Registered Dietitian through the Academy of Nutrition and Dietetics and a board-certified Health and Wellness Coach through the International Consortium for Health and Wellness Coaching. She has a Bachelor of Science in Biology and a Master’s degree in Clinical Dietetics and Nutrition from the University of Pittsburgh.

Talking and writing about food and fitness is at the heart of Claire’s ethos as she loves to use her experience to help others meet their health and wellness goals.

Claire is also a certified indoor cycling instructor and loves the mental and physical boost she gets from regular runs and yoga classes. When she’s not keeping fit herself, she’s cheering on her hometown’s sports teams in Pittsburgh, or cooking for her family in the kitchen.

Find out more about Claire’s experience here.