Are Pre-Workout Supplements Bad For You?

Feeling a Boost Doesn’t Always Mean a Stronger Body

Man with sport nutrition

Going to the gym or heading out for a run? You may have heard that you have to take your ‘pre-workout’ if you want to improve athletic performance and increase muscle strength. This buzz statement about pre-workout supplements has become the norm among athletes, active individuals, and a few athletic coaches. This is mostly because of their popularity, and not so much about any evidence supporting claims to enhance your physical fitness.

Are pre-workout promises true or just a bunch of hype to sell supplements? In order to answer this question, you need to know what a pre-workout is and how it affects your body.

What You Should Know

Pre-workout products are unregulated dietary supplements. This means the product is not reviewed or regulated by the Food and Drug Administration (FDA) for ingredients, effectiveness, and safety. Supplements have been placed under a special food category and are really not considered drugs.

Because pre-workout supplements are unregulated, manufacturers and producers can claim pretty much anything to sell their product. This seems unfair—and is—but there’s promising evidence backing a few supplements on the market. Before selecting a pre-workout or any supplement, the International Society of Sports Nutrition (ISSN) recommends that you evaluate the science behind supplement claims for enhanced athletic performance.

What Is a Pre-Workout Supplement?

Pre-workout supplements usually contain a proprietary blend, which means the label doesn’t have to break down the specific amount of each ingredient. So, you really don’t know what you’re getting with these combination pre-workout products. The primary ingredient you will find is high levels of caffeine. Other common ingredients can include dimethylamylamine, creatine, arginine, β-alanine, taurine, and phosphates. Many pre-workouts also contain additional plant-based stimulants like guarana (herbal caffeine).

Honestly, pre-workout supplements are really powerful stimulants because they do contain large amounts of caffeine. This is why you feel energized and ready to tackle an intense workout after consuming a pre-workout product. Does this supplement buzz make your body any stronger or exercise effort any better?

Research indicates some of the ingredients actually work better individually and not when combined, typical of pre-workout products. They remain popular however and taking a look at each ingredient is beneficial especially if you’re considering using a pre-workout. Here are a few common ingredients found in pre-workout products and how they function in your body:

  • Caffeine – Research indicates caffeine has a positive benefit for improved athletic performance. Caffeine is shown to increase your metabolic rate, improve endurance levels, and resistance to fatigue. It also stimulates the central nervous system (CNS), improving your brain function for a more productive and effective workout. For best results, caffeine doses are recommended to be tailored to each individual and consumed in low to moderate doses (~3-6 mg/kg of body weight). Unfortunately, pre-workout products often exceed the caffeine levels suggested leaving you unable to control what is considered your best dose. Many athletes are now turning to black coffee as a better way to control caffeine intake and improve their exercise performance.
  • Creatine – The most popular bodybuilding supplement backed by independent studies and research. Creatine is made from amino acids and concentrated in your muscle tissues. The primary role of creatine is supplying energy to your cells and maintaining cellular balance. It enhances athletic performance by increasing ATP (adenosine tri-phosphate) used during quick bursts of energy like sprinting or weightlifting. According to a review of over 80 studies published in the Journal of the International Society of Sports Nutrition, creatine supplementation was effective for muscle growth, increased strength, and improved performance in high-intensity interval training (HIIT). The recommended standard effective daily dose of creatine is 5 grams loaded over time, cycled, and best taken as an individual supplement.
  • Arginine – This essential amino acid is part of the branch-chained amino acid group and necessary for producing protein. Arginine is also used to create nitric oxide, a compound that relaxes your blood vessels for better blood flow and oxygen exchange. There is also a possible health benefit for those suffering from heart problems or hypertension. Little scientific evidence is available to support claims promoting improved athletic performance or increased functional capacity in athletic individuals. More research is needed to evaluate the role of arginine supplementation on exercise performance.
  • β-alanine – Also known as beta-alanine, this is a naturally occurring amino acid produced in your liver. It’s also acquired through consuming foods like poultry and meats, and supplementation. β-alanine helps increase carnosine in your muscle tissue improving cellular function. Beta-alanine supplementation has been shown to delay the onset of neuromuscular fatigue and enhance athletic performance. Dosing of β-alanine will differ per person because of the potential for adverse effects including paraesthesia (tingling) for example. Because pre-workout products combine ingredients without having to disclose the levels of each one eliminates your ability to dial back the dose if you do experience negative side effects. More research is needed to determine the effects of beta-alanine on strength and endurance performance lasting longer than 25 minutes according to a position stand published in the Journal of the International Society of Sports Nutrition.
  • Taurine – One of the most abundant amino acids in the brain, retina, muscle tissue, and organs throughout the body. Taurine has a wide variety of functions in the central nervous system (CNS) and helps with human development. It’s naturally occurring in your body but also obtained by eating animal and fish protein. You will find taurine included in most energy drinks and it can be purchased as a supplement. Taurine functions as a neurotransmitter in the brain, stabilizes cell membranes, and regulates the transport of essential nutrients throughout your body. Although taurine has many important metabolic roles, there appears to be conflicting evidence to support any claims of improved athletic performance. Evidently, ingesting taurine and caffeine together—a typical occurrence with pre-workout products—actually increases muscle fatigue according to research published in the Journal of Strength and Conditioning.
  • Phosphates – Phosphates include alkalinizing agents like sodium bicarbonate, sodium citrate, and phosphate salts. Phosphates help with cell structure, energy transport, and numerous other functions essential to your health. They appear to improve athletic performance by neutralizing the acids that build up in muscle during exercise. Most mineral supplements seem to be safe in small doses and used short-term, but can have adverse effects if taken in higher doses. Individuals suffering from kidney problems and prone to kidney stones are advised not to supplement with phosphates without consulting their physician. Other common adverse side effects may include stomach upset, bloating, and nausea.
  • Guarana – A plant common to Brazil producing seeds used for a variety of health reasons. Guarana functions as a stimulant and contains twice the amount of caffeine found in coffee beans. Guarana is said to improve athletic performance, increase mental focus, and decrease muscle fatigue. Some research indicates lower doses of guarana (75mg) to have a more positive effect on physical output without concern for toxicity than higher doses. Caffeine has been shown to enhance your workouts at lower concentration levels and, unfortunately, pre-workout products eliminate your ability to reduce the intake.
  • Betaine – An amino acid shown to improve body composition and promote muscle growth. Betaine is found in many foods including spinach, beets, and whole grains. It works in the body by maintaining liver function, detoxification, and cellular functioning. Betaine also helps your body process fats. A small study on betaine supplementation did show betaine supplementation improved body composition, muscle size, and work capacity.
  • Nitrates – A compound found in numerous foods and abundant in leafy greens, vegetables, and beetroot. After consuming a nitrate-rich food, your body converts it to nitrite and further uses it to make nitric oxide. Nitric oxide has an important role in regulating your metabolic and vascular functions. During exercise, nitric oxide is said to increase blood flow, improve lung function, and strengthen muscle contraction. Many athletes are supplementing with beetroot juice to improve cardiorespiratory endurance and athletic performance.

Effects on Exercise Performance and Muscle Strength

Pre-workout products do heighten your exercise performance, but that is really due to the caffeine content and not necessarily the supplement. You may be wasting your money and better off drinking a cup or two of black coffee prior to working out, especially since many supplement ingredients are more effective taken alone and not together in a mystery proprietary blend. The following studies have examined the effectiveness of pre-workout supplements on athletic performance and muscle strength:

  • A study published in the American Journal of Health-System Pharmacy indicated insufficient evidence is available for combination pre-workout products as being effective for performance enhancement. Stand-alone ingredients like caffeine did show some ergogenic benefit with improved reaction time, energy, and mental focus during physical training. The safety of these products may also be a concern as individuals may consume larger than the recommended amounts.
  • Research published in the Journal of the International Society of Sports Nutrition examined if pre-workout products increased the amount of blood in muscle tissue during exercise. Increased blood flow would provide better oxygen levels to working muscles in an effort to improve performance. Results indicated pre-workout supplements didn’t really improve exercise performance. The only time blood flow to the muscle showed a significant increase was post-workout and only following an 80 percent exercise load condition. More research is required to determine which situations and athletes may benefit from using pre-workout supplementation.
  • Research published in the International Journal of Medical Sciences examined the effects of pre-workout supplements on lean mass, athletic performance, and exercise experience. The participants reported feeling more energy and better concentration during their workout compared to those taking a placebo. However, no evidence of improved body composition or exercise performance was reported.
  • Another study published in the Journal of the International Society of Sports Nutrition investigated how pre-workout supplements with or without synephrine would affect training responses during exercise in resistance-trained men. Synephrine is a compound extracted from bitter orange fruit with potent metabolism boosting effects. Results suggest pre-workout supplementation may benefit cognitive function and exercise performance during a workout, but further research is required.

A Word From Verywell

Pre-workout supplements are popular mostly because of the caffeine buzz provided during your workout. Unfortunately, they may not be the best products for improved athletic performance and muscle strength. There is also insufficient evidence to support using proprietary blends for this goal. Because of the high caffeine content in pre-workout products and potential adverse health effects, it’s a good idea to talk with your doctor before using this or any supplement.

View Article Sources