Peptides in Sports and Recovery: What Patients Should Know

What Are Peptides?

Peptides are short chains of amino acids — the building blocks of protein. They can be derived from collagen, whey, casein, or plant proteins. Because they are absorbed quickly, they may support recovery, connective tissue health, or muscle building.

Collagen Peptides: What the Evidence Says

Over the last several years, collagen peptides have been tested in randomized controlled trials and summarized in meta-analyses.

• Strength and muscle architecture: A 2024 systematic review and meta-analysis (Bischof et al., Sports Medicine) concluded that collagen peptide supplementation combined with training led to modest improvements in fat-free mass, maximal strength, and muscle architecture. The effect sizes were small to moderate, and the certainty of evidence was low-to-moderate, meaning the results are promising but not definitive [1].

• Tendon and connective tissue remodeling: Narrative reviews and RCTs suggest collagen peptides support extracellular matrix remodeling, which may improve tendon stiffness and morphology, particularly when combined with resistance training [4].

• Exercise recovery and soreness: Clinical trials have found that collagen peptides may reduce muscle soreness and fatigue after exercise and improve recovery of explosive strength following muscle damage [11,12].

• Joint health: Trials in middle-aged adults with joint discomfort have reported improvements in pain and function, making collagen attractive for people with high training loads or pre-existing joint issues [2,5].

Typical regimen studied: 10–20 g daily for 8–16 weeks, combined with structured resistance or endurance training [1–4].

Whey and Casein: The Stronger Evidence for Muscle Growth

In contrast, whey and casein proteins have been studied extensively for decades and show consistent, high-certainty benefits:

• Muscle protein synthesis (MPS): Whey significantly increases MPS after resistance exercise, driven by its high leucine content. Collagen protein, by comparison, does not increase MPS above placebo [5–6].

• Hypertrophy and strength: RCTs in both young and older adults confirm that whey and casein are superior to collagen for increasing muscle thickness, hypertrophy, and anabolic signaling [3,6–8].

• Blends: Adding collagen to whey may raise connective tissue protein synthesis, but during post-exercise recovery, the anabolic advantage still lies with whey-dominant supplementation [9].

• Head-to-head comparisons: Substituting whey with collagen does not improve muscle damage, strength recovery, or soreness indices compared to whey alone [10].

Putting It Together: What’s Best for Patients?

• For muscle growth and strength: Whey or casein remain the gold standard. The evidence here is robust and consistent.

• For tendon and joint support: Collagen peptides may offer modest benefits for connective tissue remodeling, stiffness, and soreness. Evidence is growing, but generally lower in certainty compared to whey.

• For overall recovery: A combined approach (whey for muscle, collagen for connective tissue) is sometimes used, though whey still drives the major gains in muscle.

Safety: Both collagen and whey/casein proteins are considered safe, with no significant side effects reported in large clinical studies [1–3].

Key Takeaway

• Collagen peptides are a useful adjunct, particularly for tendon health and joint recovery, but they are not a replacement for whey or casein when the goal is muscle building.

• The strongest evidence shows that whey/casein proteins remain first-line for strength, hypertrophy, and exercise recovery.

• Collagen may be most helpful for patients with joint soreness, tendon issues, or connective tissue recovery needs, especially when paired with consistent training.

References

1. Bischof K, Moitzi AM, Stafilidis S, König D. Sports Medicine. 2024;54(11):2865-2888. doi:10.1007/s40279-024-02079-0.

2. Khatri M, Naughton RJ, Clifford T, Harper LD, Corr L. Amino Acids. 2021;53(10):1493-1506. doi:10.1007/s00726-021-03072-x.

3. Zdzieblik D, Jendricke P, Oesser S, Gollhofer A, König D. Int J Environ Res Public Health. 2021;18(9):4837. doi:10.3390/ijerph18094837.

4. Holwerda AM, van Loon LJC. Nutrition Reviews. 2022;80(6):1497-1514. doi:10.1093/nutrit/nuab083.

5. Aussieker T, Hilkens L, Holwerda AM, et al. Med Sci Sports Exerc. 2023;55(10):1792-1802. doi:10.1249/MSS.0000000000003214.

6. McKendry J, Lowisz CV, Nanthakumar A, et al. Am J Clin Nutr. 2024;120(1):34-46. doi:10.1016/j.ajcnut.2024.05.009.

7. Jacinto JL, Nunes JP, Gorissen SHM, et al. Int J Sport Nutr Exerc Metab. 2022;32(3):133-143. doi:10.1123/ijsnem.2021-0265.

8. Churchward-Venne TA, Pinckaers PJM, Smeets JSJ, et al. J Nutr. 2019;149(2):198-209. doi:10.1093/jn/nxy244.

9. Aussieker T, Kaiser J, Hermans WJH, et al. Med Sci Sports Exerc. 2025;57(3):544-554. doi:10.1249/MSS.0000000000003596.

10. Robberechts R, Poffé C, Ampe N, Bogaerts S, Hespel P. Int J Sport Nutr Exerc Metab. 2024;34(2):69-78. doi:10.1123/ijsnem.2023-0070.

11. Kviatkovsky SA, Hickner RC, Ormsbee MJ. Curr Opin Clin Nutr Metab Care. 2022;25(6):401-406. doi:10.1097/MCO.0000000000000870.

12. Kuwaba K, Kusubata M, Taga Y, et al. J Int Soc Sports Nutr. 2023;20(1):2206392. doi:10.1080/15502783.2023.2206392.