Pre-Workout Supplements, BCAAs, and EAAs: Do You Really Need Them?

In the realm of fitness, pre-workout supplements, branched-chain amino acids (BCAAs), and essential amino acids (EAAs) are often marketed as performance enhancers. But how effective are they, and are they necessary for everyone?

As a registered dietitian and personal trainer, let’s delve into the science behind these supplements to provide clarity.

What Are Pre-Workout Supplements?

Pre-workout supplements are designed to boost energy, endurance, and focus during exercise. They typically contain a blend of ingredients such as caffeine, beta-alanine, creatine, citrulline malate, and amino acids. However, the efficacy and safety of these ingredients can vary.

Pre-Workout Ingredients, Functions and Dosages

1. Caffeine

• Function: Central nervous system stimulant; improves endurance, power, and reduces perceived effort.
• Research-supported dose: 3–6 mg/kg body weight (~200–400 mg for most adults) taken ~30–60 minutes pre-workout.
• Typical pre-workout dose: Often 150–300 mg — sometimes below optimal range, sometimes above, which can cause jitters or sleep issues.
• Evidence: Strong — improves performance across endurance and strength measures (JISSN, 2020)

2. Beta-Alanine

• Function: Increases muscle carnosine, buffering hydrogen ions to delay fatigue in high-intensity exercise.
• Research-supported dose: 2–5 g/day consistently over weeks (not just pre-workout)
• Typical pre-workout dose: 1.5–3 g per serving — often underdosed for maximal effect.
• Evidence: Moderate — most beneficial for 1–10 min high-intensity bouts (Saunders et al., 2017)

3. Creatine Monohydrate

• Function: Boosts phosphocreatine stores, supporting high-intensity efforts and muscle growth.
• Research-supported dose: 3–5 g/day (timing around workouts is optional).
• Typical pre-workout dose: Often 1–2 g — below research-backed amounts, meaning additional supplementation is needed for effectiveness.
• Evidence: Strong — consistently improves strength, lean mass, and performance (JISSN, 2017)

4. Citrulline Malate

• Function: May improve blood flow, reduce fatigue, and enhance endurance.
• Research-supported dose: 6–8 g ~30–60 min pre-workout.
• Typical pre-workout dose: 2–4 g — often underdosed, which may explain inconsistent results in commercial products.
• Evidence: Mixed — some studies show modest benefits, others find no effect (PMC8571142)

5. Other Ingredients

• Tyrosine, taurine, and B vitamins are sometimes included to support focus or energy metabolism, but evidence is limited.
• Proprietary blends can hide true dosages, making it difficult to evaluate efficacy or safety.

Who Might Not Need Pre-Workout Supplements

• Midday or afternoon exercisers who have eaten recently likely have circulating amino acids and glucose, making supplements unnecessary.
• Recreational or lower-intensity exercisers.
• Those sensitive to caffeine or stimulants.

Alternatives:

• Balanced pre-workout snack (carbs + protein, e.g., yogurt with fruit, banana with nut butter).
• Coffee or tea for natural caffeine.
• Proper hydration and sleep — often more impactful than supplements.

What About Amino Acid Supplements?

Another type of supplement that can be taken before a workout is an amino acid supplement, commonly branched chain amino acids or essential amino acids.

Amino acids are the building blocks of protein, essential for muscle repair, enzyme production, and recovery.

• Essential amino acids (EAAs): Must be obtained from food or supplements, can not be produced by the body.
• Non-essential amino acids: Can be produced by the body from other sources.

Complete protein sources (chicken, eggs, soy, Greek yogurt) provide all essential amino acids naturally, whereas BCAA and EAA supplements isolate them for convenience.

BCAAs vs. EAAs

BCAAs (leucine, isoleucine, valine):

• Stimulate muscle protein synthesis (MPS) but are incomplete alone — full MPS requires all nine EAAs. These tend to be easier on the stomach for many people.
• Useful: During fasted workouts, long endurance sessions, or if you cannot eat before training. (JISSN, 2017)

EAAs:

• Contain all nine essential amino acids and more effectively stimulate muscle protein synthesis.
• Useful: For fasted workouts, limited daily protein intake, or long sessions where food isn’t practical. (PMC10561576)

Key takeaway: Daily protein intake being adequate matters most. EAAs are typically more efficient than BCAAs but some may find BCAAs easier to tolerate and can still have an effect on preventing muscle breakdown.

Practical Recommendations

1. Prioritize food first: Balanced meals and snacks with protein every 3–4 hours.
2. Pre-workout fueling: Consume carbs + protein typically 1-2 hours before exercise.
3. Use supplements strategically:
   • A pre-workout supplement may be helpful for an energy boost (but for the casual exerciser coffee or caffeine containing beverage of choice is usually sufficient!)
   • BCAAs can be helpful for fasted workouts (such as right in the morning) but tend to be less efficient/effective as EAAs
   • If you’ve had a protein containing meal/snack at least a few hours prior you likely have enough circulating amino acids. Having a protein containing snack after or a meal within a few hours can prevent muscle breakdown and stimulate muscle protein synthesis.
4. Choose quality products: Look for third-party tested brands and check ingredient amounts vs research doses.

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So What’s The Final Verdict On Workout Supplements?

Pre-workout supplements, BCAAs, and EAAs can enhance performance in specific situations, but they are not required for most exercisers.

Focus on consistent nutrition, hydration, sleep, and recovery — these foundations have the largest impact on energy, strength, and progress. Supplements are simply tools to fill gaps or provide convenience.