Pre-workout drinks are common among many athletes, claiming that they improve their performance in the weight room or on the field, but are they worth the hype and safe to consume? Before we discuss the safety, we need to dive into what ingredients are found in pre-workout supplements and the claims attributed to enhancing sports performance.
Common Ingredients
Ingredients commonly found in pre-workout supplements include caffeine, BCAAs (branch chain amino acids), taurine, beta alanine, creatine, Vitamin B12, and citrulline. There are many more questionable ingredients listed as “proprietary blend”, code word for we don’t want to disclose exactly what’s in our product, which should be a red flag for you. Since sports supplements are not regulated by the FDA, and if they are not certified by a 3rd party company like NSF Sport or Informed Choice, we really don’t know what is listed on the label is exactly in the product. Moving forward, if you do choose to use a pre-workout supplement, avoid those listing “proprietary blend” and those that are not 3rd party certified.
However, some of the ingredients found in pre-workout have been studied to be effective to give you that extra boost of energy and reduce your perceived effort to be able to push a little harder or faster during your workout or competition. Let’s review the research and see which ones can be helpful.
Caffeine
Caffeine is a primary ergogenic aid providing quick energy to reduce your perceived effort. It peaks in your bloodstream within an hour after taking it to make you feel like you can go further and/or faster without excessive fatigue. Common dosages include 3 to 6 mg/kg body weight. If you weigh 150# (68 kg) you can ingest approximately 200 to 400 mg. Most pre-workout caffeine amounts range from 90-300 mg/serving, so if you are sensitive to caffeine, experiencing GI issues, elevated heart rate or blood pressure when consuming caffeine, it’s advisable to consume the lower dose or to avoid it all together. Teen athletes should limit their intake of caffeine to less than 200 mg daily to reduce symptoms of irritability, heart palpitations, anxiety, and sleep disturbances.
BCAAs
Branched-chain amino acids (BCAAs) consist of the three essential amino acids (AA), isoleucine, leucine and valine. This means your body cannot make these AA and you must get them from food. AA are the building blocks of protein and specifically, leucine, is the BCAA that is helps with muscle tissue repair and rebuilding; however, this does not mean ingesting BCAAs alone are effective in increasing muscle protein building. You can get more BCAAs from eating whole protein foods such as milk, cheese or meat. In addition, the research is lacking to justify taking BCAAs before exercise to improve sports performance and muscle strength, but some limited studies show that it can lower muscle soreness.
Taurine
Taurine is an AA from animal protein foods and is found in your muscle. Its role is to regulate sugar (glucose) and fat, energy metabolism, and to reduce inflammatory modulation. Common doses range 500 mg/day to 10 g/day found in capsules or sports-nutrition beverages. Blood concentrations increase after 10 min of ingestion, peak within 1 hour, and return to baseline within 6.5 hours.
There is no clear evidence that taurine in pre-workout supplements provides additional sports performance benefits. Some research shows that it can negatively interact with caffeine, which is also commonly found in pre-workout, increasing the risk of cardiovascular issues.
Beta alanine
Beta-alanine is an amino acid that does not contribute to protein building, but produced by the liver, but you can also get it from eating poultry and meat. It’s usually ingested in a pill or powder form and often found in pre-workout supplements.
To simplify this process, beta-alanine increases carnosine levels in muscle to buffer acid formed in the muscle when performing intense exercise. Carnosine can slow the decline in muscle pH (acidity) and contribute up to 15% to total buffering capacity. In other words, beta-alanine supplementation reduces lactic acid allowing athletes to perform at higher intensities for a longer period.
Research suggests beta-alanine requires a chronic loading dose of 3-6 grams daily, divided in doses of 2 grams or less, over at least 4 weeks to increase muscle carnosine stores by 30-60%. To see greater muscle carnosine loading, a larger dose of 6 grams, divided into 4 equal doses can be advantageous.
Ingesting a single large dose of beta-alanine can cause paranesthesia (i.e. tingling like pins and needles) and flushing. This symptom can disappear within 60 to 90 minutes following supplementation and is not considered harmful but can impact sports performance related to rapid changes in pH and the inability to load the muscle.
Overall, since dosage of beta-alanine in most pre-workout supplement is less than what is recommended to gain the benefits, consuming a single, small dose of beta-alanine in pre-workout before training would not be effective.
Creatine
Creatine is a well-researched supplement that shows benefits for athletes of all ages and types of sports. Researchers use to think it was only helpful for improving muscle gains for high-intensity activities (weight training, sprinting), but lately it has been shown to be beneficial for endurance and aging athletes as well to maintain muscle mass and help with muscle recovery. Most pre-workout supplements don’t contain the optimal dosage of 20 grams (g) per day for 5 days to restore low levels. If you don’t need to restore levels, a maintenance dose of 5 g/day is recommended for 30 days, but pre-workout supplements often fall short of the recommended amounts just containing 1-3 grams; therefore, would not be an effective dose to gain the benefits.
Vitamin B12
Vitamin B12 plays a role in several different processes in the body, including energy production, amino acid and DNA synthesis, blood cell formation, and brain and nerve cell function. If you are truly deficient, taking B12 supplements is necessary to help with sports performance. But if your B12 levels are within a normal range, taking extra B12 is not going to act as a stimulant and help you gain that competitive edge if levels exceed normal ranges.
B12 cannot be made in the body, so it’s essential you get it from your diet from animal sources; however, taking B12 in your pre-workout has not been proven to fix any deficiencies and/or improve protein building. The NIH (National Institute of Health) recommends getting about 2.4 micrograms (mcg) of Vitamin B12 daily. If you eat animal products (milk, eggs, meat and/or cheese), you are most likely getting enough B12, but if you are vegan or cannot absorb B12 related to gut issues, supplementation maybe necessary to prevent deficiencies.
Overall, there are no studies that support taking B12 in pre-workout or as a separate supplement to improve sports performance, especially when there is not a deficiency present.
Citrulline Malate
Citrulline comes in two forms, L-citrulline and citrulline malate (CM). L-citrulline is a non-essential amino acid, meaning your body can make it and you don’t have to get it from food. It is produced by the liver and intestine and is also found in foods such as squash, cucumber, pumpkin, and watermelon.
Citrulline is not involved with protein building, but it plays a role in the urea cycle where it is converted to another amino acid, L-arginine to be converted to nitric oxide (NO). NO helps to regulate blood pressure, cell signaling, and immune response to enhance blood flow to exercising muscles and reduce muscle soreness.
L-citrulline is produced in the body and can help boost NO levels; whereas CM is the addition of malic acid which impacts how your body produces energy. CM can increase blood flow and nutrients to exercising muscles, potentially improving exercise performance.
Common dosing for L-citrulline is 2.4-6.0 grams per day for a minimum of seven days, whereas it is suggested to consume 6 to 8 grams of CM one hour before exercise without a loading phase. However, research is inconsistent on whether citrulline benefits athletes. In small studies, higher doses of CM (15 g) may increase the ergogenic effects, but additional research is needed in larger populations to confirm its benefit.
In addition, watermelon contains L-citrulline, but you would have to consume 30 cups of diced watermelon to contain enough citrulline to be beneficial, and it would not contain a sufficient dose of the malate component.
Overall, there is not enough sufficient evidence to support consuming citrulline found in pre-workout, but more research is needed to identify beneficial amounts in larger studies before recommending it for athletes.
Take Home Message
Despite the many claims pre-workout supplements make to increase sports performance and reduce muscle soreness, there have not been enough studies to support the claims. The doses of most ingredients in pre-workout supplements are too small for it to positively impact your training, except for caffeine which has been extensively researched to reduce your perceived effort so you can train harder and longer without experiencing early fatigue.
Before training it’s recommended to be well-hydrated, eat easily digesting carbohydrates found in fruit, grains, or carb-containing beverages/Gu or gels to provide sugar to your working muscle and brain. In addition, caffeine can provide that additional energy boost. All the additional ingredients may work for some, but this most likely a placebo effect instead.
References:
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3. Kurtz JA, VanDusseldorp TA, Doyle JA, et al. Taurine in sports and exercise. J of International Society of Sports Nutrition. 2021.18 (39).
4. Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018.Apr; 52 (7):439-455.
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