Does protein powder help athletes?
The effectiveness of protein supplements on athletic performance and post-exercise recovery − a Bayesian multilevel meta-analysis of randomized controlled trials
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
All significant benefits of protein disappeared when total calorie intake was matched between groups.
Most athletes and coaches assume protein has unique metabolic or muscle-building effects, but this study suggests those benefits vanish without a caloric surplus—challenging decades of supplement marketing.
Practical Takeaways
If you're not eating enough, adding protein may help—but so would adding any calories.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
All significant benefits of protein disappeared when total calorie intake was matched between groups.
Most athletes and coaches assume protein has unique metabolic or muscle-building effects, but this study suggests those benefits vanish without a caloric surplus—challenging decades of supplement marketing.
Practical Takeaways
If you're not eating enough, adding protein may help—but so would adding any calories.
Publication
Journal
Journal of the International Society of Sports Nutrition
Year
2025
Authors
Shiao Zhao, Xiaoyu Zhang, Taihe Liang, Sanfan Ng, Yiran Liu, Ziheng Ning
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Claims (5)
Protein supplements might give athletes a small boost in endurance, especially when taken with carbs—but it could just be because they're eating more calories overall.
Athletes taking protein might get stronger, but it could just be because they're eating more total calories — not because of the protein itself.
Protein supplements might help your muscles refill energy faster after a workout compared to just carbs — but it could just be because they add extra calories, not because protein itself speeds up recovery.
Taking about an extra gram of protein per pound of body weight every day — mostly from supplements — might help athletes perform their best, but it's hard to be sure because most studies don’t account for total calories.
Taking protein supplements for several weeks might help athletes perform better than taking them just once, but we’re not totally sure because the studies didn’t control for total calorie intake.