Caffeine Before Workouts for Muscle Growth: What the Science Really Shows

Caffeine Before Workouts for Muscle Growth: What the Science Really Shows

• Caffeine before workouts for muscle growth may help increase muscle size over time
• Research suggests caffeine improves training quality, not just energy
• Caffeine before workouts for may improve muscle size, but the effect appears modest and indirect
• A common research dose is 3 milligrams per kilogram of body weight, which equals roughly 1–3 cups of coffee depending on body size
• Most evidence shows caffeine for muscle growth improves performance, but does not consistently increase muscle mass on its own

Why Caffeine Before Workouts for Muscle Growth Is Getting Attention

Walk into any gym, and you’ll see it everywhere—coffee cups, pre-workout drinks, and caffeine pills. Most lifters use caffeine for one simple reason: it helps them feel more awake and ready to train. But lately, a more interesting question has come up: Can caffeine before workouts for muscle growth actually help you build more muscle over time?

A recent study by Eshaghian and colleagues (2026), published in Sport Sciences for Health, looked beyond short-term performance and focused on real physical changes. Instead of asking whether caffeine helps you lift more today, the researchers asked whether caffeine for muscle growth could influence how your body adapts after weeks of training.

This matters because if caffeine also supports caffeine and muscle mass gains, it becomes more than just a quick boost—it becomes part of a long-term strategy.

Review of the Literature: What We Know About Caffeine for Muscle Growth

Most research on caffeine focuses on performance. And to be fair, the evidence there is strong.

For example, Giráldez-Costas et al. (2021) found that caffeine improved lifting speed and power output. In simple terms, people were able to perform reps with more force and better quality. Similarly, Grgic et al. (2021) showed that caffeine increased the total amount of work performed during resistance training. That means more reps, more effort, and potentially a stronger stimulus for adaptation.

Now, here’s where it gets interesting.

While these studies did not consistently show greater strength gains, they point toward something important: caffeine for muscle growth may work indirectly by improving how you train.

And that leads to a key idea:

• The best way to use caffeine for muscle growth is not just to lift heavier once, but to train slightly better every session.

Several studies have found no meaningful effect of caffeine on muscle hypertrophy.

Example: Fimland & Sæterbakken (2011)

• Used caffeine at 6 mg/kg
• Found no improvement in hypertrophy-style training performance
• No evidence of increased muscle growth

Large reviews (Grgić et al., 2018) conclude:

• Caffeine reliably improves performance
• But does not consistently increase muscle mass

This means that while caffeine for muscle growth is possible, it is not guaranteed or consistent across studies.

Over time, those small improvements can add up and contribute to caffeine and muscle mass development. Caffeine is one of the most widely used performance enhancers in sport—and for good reason. These effects are typically seen with doses between 3 and 9 milligrams per kilogram of body weight, taken about 60 minutes before training.

What Does 3 mg/kg Look Like in Real Life?

In the Eshaghian study, participants consumed 3 milligrams per kilogram of body weight.

Here’s what that means in practical terms:

• 150 lb (68 kg) person → ~200 mg caffeine
• 180 lb (82 kg) person → ~245 mg caffeine
• 200 lb (91 kg) person → ~275 mg caffeine

That’s roughly equal to:

• 2 to 3 cups of strong coffee
  (since one cup contains about 80–100 mg of caffeine)

This makes the study highly practical, because it reflects real-world intake levels.

The Study: Caffeine Before Workouts for Muscle Growth Over Six Weeks

To explore this idea further, Eshaghian et al. (2026) conducted a randomized controlled trial.

They recruited twenty-eight recreationally active men, with twenty-six completing the study. Participants followed a structured upper-body training program three times per week for six weeks.

The design was straightforward:

• One group consumed caffeine before workouts in the morning. 3 mg/kg before each workout
• The other group took a placebo
• Neither group knew which supplement they received

The researchers measured:

• Strength (maximum weight lifted)
• Muscular endurance (repetitions performed)
• Muscle thickness (a reliable indicator of muscle size)
• Body composition

This allowed them to directly assess whether caffeine for muscle growth leads to measurable changes in muscle size.

Results: What Happened With Caffeine Before Workouts for Muscle Growth

After six weeks, both groups improved—as expected with consistent training.

However, the caffeine group showed a key difference.

Greater Increases in Muscle Size

Participants using caffeine before workouts for muscle growth experienced significantly greater increases in biceps and triceps muscle thickness.

This suggests a meaningful link between caffeine and muscle mass, at least within the context of this study.

No Additional Strength Gains

Despite the increase in muscle size, strength gains were similar between groups.

This might seem surprising, but it highlights an important point:

Muscle growth and strength do not always increase at the same rate, especially over short periods.

Important Context

While these findings support caffeine for muscle growth, they should be interpreted carefully:

• The study lasted only six weeks
• The sample size was relatively small
• Participants were recreationally trained men

So while the results are promising, they are not definitive.

How Caffeine for Muscle Growth May Work

So how can caffeine increase muscle size without increasing strength?

The answer likely comes down to training quality.

Improved Training Effort

Caffeine helps reduce perceived effort. In simple terms, workouts feel slightly easier, even when you are working hard.

This can help you:

• Push closer to failure
• Maintain intensity across sets
• Stay mentally focused

Over time, this improved effort can support caffeine and muscle mass gains.

Increased Training Volume

Caffeine has been shown to increase total work performed. Even small increases—like one extra repetition per set—can accumulate. Across weeks of training, this added volume may contribute to caffeine for muscle growth.

However, it is important to note: Increased training volume is associated with muscle growth, but it does not guarantee it.

Small Improvements, Big Impact

The real value of caffeine before workouts for muscle growth is consistency.

It is not about one perfect workout. It is about showing up and performing slightly better, again and again.

And that is often what drives long-term progress.

Practical Applications: The Best Way to Use Caffeine for Muscle Growth

Let’s translate this into something practical.

1. Use Caffeine Strategically

The best way to use caffeine for muscle growth is to take it before demanding workouts where performance matters most.

This helps maximize effort when it counts.

2. Focus on Training Quality

Caffeine is not magic. It works best when it enhances what you are already doing.

Using caffeine before workouts for muscle growth should help you:

• Train harder
• Stay consistent
• Improve execution

3. Do Not Overestimate Its Role

While caffeine for muscle growth can help, it is not the main driver of results.

Muscle growth still depends on:

• Progressive overload
• Sufficient calorie intake
• Adequate protein consumption
• Recovery and sleep

Caffeine supports these factors—it does not replace them.

Conclusion: Should You Use Caffeine Before Workouts for Muscle Growth?

The current evidence suggests a clear but nuanced answer.

Using caffeine before workouts for muscle growth may help increase muscle size over time. However, the effect appears to be indirect—driven by better training performance rather than a direct muscle-building mechanism.

When combined with existing research, the takeaway is simple:

• Caffeine improves workout performance
• It can increase training volume
• And over time, it may support caffeine and muscle mass gains

So while caffeine will not transform your results overnight, it can provide a small, meaningful advantage.

And in the long run, those small advantages often add up.

Frequently Asked Questions

Is caffeine good for muscle growth or just energy?
Caffeine can do both. While most people use it for energy, research suggests caffeine for muscle growth may improve training quality, which can support muscle gains over time.

What is the best way to use caffeine for muscle growth?
The best way to use caffeine for muscle growth is to take it before workouts where performance matters most, allowing you to train harder and maintain intensity.

Does caffeine increase muscle mass directly?
Caffeine does not directly build muscle, but it may support caffeine and muscle mass gains by improving workout performance and training volume.

Should you take caffeine before every workout?
Not necessarily. Using caffeine before workouts for muscle growth works best when used strategically rather than relying on it every session.

References

Eshaghian, S., Moghaddam, A., & Fathi, R. (2026). Six weeks of caffeine supplementation enhances muscle thickness without augmenting strength gains: A randomized controlled trial. Sport Sciences for Health, 22(1), 12. https://doi.org/10.1007/s11332-025-01609-1

Giráldez-Costas, V., et al. (2021). Effects of caffeine supplementation on resistance training adaptations. Frontiers in Nutrition. https://doi.org/10.3389/fnut.2021.622564

Grgic, J., et al. (2021). Chronic caffeine intake and resistance training adaptations. Nutrients, 13(10), 3367. https://doi.org/10.3390/nu13103367

Fimland, M. and Sæterbakken, A. (2011). No Effects of Caffeine on Muscle Hypertrophy-Style Resistance Exercise. Journal of Caffeine Research, 1(2), 117-121. https://doi.org/10.1089/jcr.2011.0014