Does coffee make your arms bigger?
Six weeks of caffeine supplementation enhances muscle thickness without augmenting strength gains—a randomized controlled trial
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Caffeine increased muscle thickness without improving strength or body composition.
Most people believe caffeine enhances performance and muscle growth holistically—this study shows it can trigger localized hypertrophy without functional gains, which contradicts common supplement marketing.
Practical Takeaways
If you want to maximize arm growth, try taking 300–400mg of caffeine (5mg/kg for a 70kg person) 60 minutes before upper-body workouts.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Caffeine increased muscle thickness without improving strength or body composition.
Most people believe caffeine enhances performance and muscle growth holistically—this study shows it can trigger localized hypertrophy without functional gains, which contradicts common supplement marketing.
Practical Takeaways
If you want to maximize arm growth, try taking 300–400mg of caffeine (5mg/kg for a 70kg person) 60 minutes before upper-body workouts.
Publication
Journal
Sport Sciences for Health
Year
2026
Authors
Ahmadreza Eshaghian, M. G. Moghaddam, M. Fathi
Related Content
Claims (6)
Taking caffeine supplements for six weeks while doing strength training does not lead to measurable improvements in maximum strength, endurance, or body fat and muscle mass in men who exercise regularly, even though their muscles may become slightly thicker.
In recreationally active men, caffeine may help increase muscle thickness slightly during the first 6 weeks of strength training, but it does not lead to greater muscle growth or improved performance over the long term.
In recreationally active men, taking a specific dose of caffeine before upper-body workouts three times a week for six weeks is linked to a larger increase in biceps muscle thickness compared to a placebo, but does not lead to greater gains in strength or changes in body composition.
Taking caffeine supplements during upper-body weight training may lead to greater increases in the size of the biceps and triceps muscles compared to other muscles, without changing overall body adaptations in men who exercise regularly.
Taking caffeine while doing resistance training does not lead to meaningful changes in body fat or muscle mass over six weeks in active men, even though some muscles may appear thicker.