Gaelic football and hurling are physically unforgiving sports. Between explosive sprints, sharp changes in direction, and constant collisions, there’s no shortage of stress being placed on your body - particularly your tendons, ligaments, and joints. And over time, that wear and tear adds up. 

Understanding these demands, it’s no surprise that collagen supplements have gained popularity among GAA athletes aiming to improve recovery, protect against injury, and keep their bodies performing week after week.

But like anything in nutrition, the real question is - does it actually help? Or is it just another trend wrapped in good marketing?

In this article, we’re going to break it down. From the basics of what collagen actually is, to the mechanisms behind how it could support performance and injury resilience. And more importantly, we’ll look at what the evidence really says - so you can make more informed decisions about whether it’s worth including in your own routine.

What is Collagen and Why Does it Matter for Athletes?

Collagen is the most abundant protein in the human body, accounting for around 30% of total protein content. It acts as the scaffolding that holds tissues together - providing structure, strength, and elasticity to connective tissues like tendons, ligaments, cartilage, skin, and bones. Without sufficient collagen, these tissues become weaker, more prone to injury, and slower to repair.

What makes collagen unique is its amino acid profile. It’s particularly rich in Glycine, Proline, and Hydroxyproline - three amino acids that play a direct role in forming and maintaining the extracellular matrix, the network that gives connective tissues their structure and resilience.

For athletes, this is especially important. The repeated high-impact movements, directional changes, and physical collisions seen in Gaelic games create constant microstrain on these tissues. Over time, that load can break down collagen faster than the body is able to replace it, increasing the risk of overuse injuries and extending recovery time.

This is where collagen supplementation comes into play. Most products come in the form of hydrolyzed collagen peptides - essentially collagen that’s been broken down into smaller fragments, making it easier to absorb and transport in the bloodstream. Once absorbed, these amino acids act as raw materials to support collagen synthesis in tendons, ligaments, cartilage, and bone.

Types of Collagen Relevant to GAA Athletes

Although 28 types of collagen have been identified in the human body, it’s types I, II, and III that matter most in the context of sport and performance (Shoulders et al, 2009). Each plays a distinct role in the connective tissues most exposed to stress during training and competition:

• Type I Collagen – This is the most abundant form, making up roughly 90% of the body’s total collagen. It’s the dominant type found in tendons, ligaments, and bones - key structures under constant load in Gaelic football and hurling. Type I collagen provides tensile strength and structural integrity, helping tissues resist tearing and withstand repetitive mechanical stress.
  
  
• Type II Collagen – Found primarily in cartilage, Type II collagen plays a critical role in joint health. It forms the framework that gives cartilage its cushioning and shock-absorbing properties - particularly important for movements involving impact, jumping, or directional changes.
  
  
• Type III Collagen – Typically found alongside Type I, Type III collagen supports elasticity and flexibility in soft tissues like ligaments and skin. It helps maintain the suppleness of connective tissues, allowing them to stretch and recoil without damage - essential for injury prevention during dynamic movements.
   

Collagen Absorption, Bioavailability and Practical Implications

Most collagen supplements on the market use hydrolyzed collagen peptides - essentially collagen protein that’s been broken down into smaller fragments to make it easier for your body to absorb. These peptides typically have a molecular weight in the range of 2,000 to 3,500 Daltons, which research has shown to be effectively absorbed and utilized by the body (Inacio et al, 2024). 

Upon ingestion, the constituent amino acids (glycine, proline, and hydroxyproline) are rapidly absorbed into the bloodstream, reaching peak plasma concentrations approximately 60 - 90 minutes post-ingestion (Lee et al, 2023).

Some supplements now promote even smaller forms, like dipeptides and tripeptides, which have molecular weights below 500 Daltons. In theory, these may be absorbed more rapidly due to their smaller size. However, in practice, the evidence isn’t strong enough to suggest they offer any clear performance advantage. For example, recent meta-analysis data from Bischof et al. (2024) and Khatri et al. (2021) based their conclusions on standard peptide forms, and still reported consistent positive outcomes across, which we’ll explain later. 

You’ll also see some people using Gelatin as a collagen source. It’s worth noting that gelatin has a much higher molecular weight (~100,000 Daltons), which generally makes it theoretically less efficient in terms of absorption. That said, some studies have shown benefits with gelatin supplementation too. However, from a practical standpoint, hydrolyzed collagen peptides may be considered the better option, offering higher bioavailability, more predictable dosing, and greater consistency in terms of how the body utilises it.

This becomes even more relevant when you consider recent research suggesting that higher doses of collagen, in the region of 15 - 30 grams, may be more effective for stimulating collagen synthesis and achieving meaningful tissue adaptations (Lee et al, 2024; Nulty et al, 2024). Hitting those kinds of doses with gelatin isn’t easy. You’d need to consume a fairly large volume of collagen rich jellies to get the same quantity of usable peptides, which makes it much more impractical for day to day use. Hydrolyzed peptides, on the other hand, allow you to hit those targets consistently and without the added prep or guesswork.

For athletes, my personal recommendation would be choosing a hydrolyzed product with a reliable dose. Additionally, if the label lists molecular weight or confirms hydrolyzation, that’s generally a good sign you’re getting something worthwhile.

Collagen Supplementation for Tendon Health and Injury Management

One of the most compelling reasons GAA athletes look to collagen supplementation is for its potential role in supporting tendon health and reducing injury risk.

The most recent and robust evidence we have comes from Bischof et al. (2024), a systematic review and meta-analysis of 19 randomized controlled trials. It showed clear structural changes with collagen peptide (CP) supplementation. Specifically, athletes who supplemented consistently experienced a significant increase in tendon cross-sectional area (CSA), with a pooled effect size of 0.67. In simple terms, collagen peptides appear to support tendon growth, particularly in key sites like the patellar and Achilles tendons, when combined with regular training.

This increase in CSA implies a thicker tendon that could, in theory, better tolerate repeated loading and distribute mechanical strain more effectively across the tissue (stress = force/CSA). From a physiological standpoint, this makes sense: a thicker tendon may act as a buffer against strain accumulation, potentially lowering injury risk or delaying the onset of overload symptoms.

That said, structural change doesn’t necessarily mean functional change. 

Despite those structural adaptations, Bischof’s meta-analysis found no significant effect on tendon mechanical properties - things like stiffness, elasticity, or Young’s modulus. The pooled effect size here was just 0.05, meaning that while tendons may become physically larger, they don’t necessarily become “stronger” or more mechanically robust. This might explain why improvements in actual performance or injury rates haven’t been as consistently reported across studies.

That nuance matters. Tendon hypertrophy is one thing, while mechanical functionality is another. 

These findings are supported by earlier research like Shaw et al. (2017), which showed that 15g of gelatin (a collagen source), enriched with vitamin C and consumed one hour prior to a brief skipping protocol, significantly increased markers of collagen synthesis in the blood - specifically PINP. While this indicates systemic upregulation of collagen production, it doesn’t confirm whether those increases lead to functional improvements like enhanced stiffness or performance outcomes.

However, more recent work has begun to challenge the idea that mechanical properties are unaffected. A study by Nulty et al. (2025) provided 30g of hydrolysed collagen alongside resistance training in middle-aged men and observed not just increases in tendon CSA, but also improvements in tendon stiffness and Young’s modulus. Compared to resistance training alone, collagen supplementation appeared to enhance both structure and mechanical function - suggesting that higher doses, longer durations, or more targeted training protocols may unlock additional benefits.

Supporting this further, Lee et al. (2024) demonstrated a clear dose-response relationship for collagen synthesis. When paired with 50 mg of vitamin C, a 30g dose of collagen peptides significantly increased PINP concentrations compared to both 15g and placebo. They also found that key collagen-building amino acids (glycine, proline, and hydroxyproline), peaked in circulation roughly 60 minutes post-ingestion, reinforcing the importance of both timing and dosage for effective collagen synthesis.

Taken together, these findings paint a fairly coherent picture:

• Collagen peptides, particularly when taken pre-training and paired with vitamin C (≥50 mg), stimulates collagen synthesis.
  
• That synthesis can translate into structural changes in tendon tissue, especially in terms of tendon thickness.
  
• Under the right conditions - higher doses and consistent resistance training - mechanical improvements may also follow.
  

That said, increasing tendon size alone may still be a meaningful outcome - particularly for athletes managing chronic tendon niggles, returning from injuries, or just trying to stay more robust through a demanding training schedule. A thicker tendon may not be a magic bullet, but it could mean a more resilient one, better equipped to handle the cumulative loading of GAA week in, week out.

Practical Insight: Based on the current evidence, a daily dose of 10-15 grams of hydrolyzed collagen peptides, taken 60 minutes pre-training and paired with ~50 mg of vitamin C, remains the most evidence-backed approach. But if you’re dealing with more persistent tendon issues or higher training volumes, there may be merit in exploring slightly higher doses, as newer data continues to build. 

Collagen Supplementation and Muscle Growth

Although collagen supplementation is sometimes marketed as beneficial for muscle hypertrophy, the current evidence suggests it is considerably less effective than complete protein sources like whey or casein. Mechanistically, muscle growth is driven by increasing muscle protein synthesis (MPS) beyond muscle protein breakdown over time - a process that relies heavily on the availability of essential amino acids, particularly leucine, to activate the mTOR pathway.

This is where collagen falls short. It contains very little leucine, roughly 5.5 times less than whey, and lacks tryptophan entirely, making it an incomplete and lower-quality protein source for stimulating MPS (Oikawa, 2020). In practical terms, this means collagen has limited capacity to initiate the signalling required for meaningful muscle hypertrophy.

This is further supported by a recent study from McKendry et al. (2024), which directly compared the effects of supplementing with 50 grams of either Collagen, Pea, or Whey protein per day on MPS rates. Both whey and pea protein significantly elevated MPS, whereas collagen had no meaningful effect. The researchers attributed this to the low leucine content in collagen.

Practical Insights: GAA athletes focused on muscle growth should prioritise complete protein sources rich in essential amino acids. While collagen may still have a role in supporting joint and connective tissue health, its role in directly driving muscle hypertrophy appears to be limited when compared to higher quality protein sources. 

Collagen Supplementation for Recovery and Muscle Soreness

There’s growing interest among GAA players in using collagen supplements as a way to support post-training recovery - particularly to reduce muscle soreness after hard sessions. Whether it’s a heavy gym block, pitch sessions, or a return to play phase, delayed onset muscle soreness (DOMS) is a common issue - often linked to eccentric loading and unfamiliar movement patterns that cause low level muscle damage and inflammation.

But how does collagen stack up when it comes to supporting recovery in this context?

A recent trial by Kuwaba et al. (2023) looked at this in a group of untrained, middle-aged men. Participants took 10g of collagen peptides per day for a week leading up to, and two days after, a bout of bodyweight squats designed to cause eccentric muscle damage. Collagen supplementation resulted in modest reductions in muscle soreness (VAS scores) 24 and 48 hours post exercise. However, there were no meaningful changes observed in blood markers of muscle damage like creatine kinase (CK) or lactate dehydrogenase (LDH).

At first glance, that might suggest a role for collagen in reducing discomfort after exercise. However, it’s important to take the context into account. This was a low load training protocol in an untrained population, and collagen wasn’t compared against established recovery tools like high quality protein. So while the findings are interesting, they’re limited in what they can tell us about trained athletes or high intensity workloads.

To explore this further, a 2024 study by Barclay et al. tested collagen more rigorously. In this trial, 60 young men were given either 25g of collagen hydrolysate, a matched dose of dairy protein (whey-casein blend), or placebo following repeated eccentric running. Across 72 hours of follow-up, neither collagen nor dairy protein significantly improved soreness, strength recovery, or markers of muscle damage compared to placebo. The researchers concluded that collagen supplementation did not meaningfully enhance recovery in this context.

Practical Insights:  Exercise-induced muscle damage is primarily driven by eccentric stress and the resulting inflammatory response. While collagen might offer mild symptom relief in untrained populations, there’s no solid evidence it improves recovery outcomes in athletes, especially when compared to high-quality protein. Stick to 20 - 40 g of high-quality protein post-exercise to support tissue repair. Collagen can still play a supporting role in connective tissue health, but it shouldn’t be seen as a routine recovery supplement for muscle soreness based on current evidence.

Conclusion and Practical Takeaways

For Collagen, the strongest evidence points toward supporting tendon health, especially when dosed correctly (10-15g with vitamin C, pre-training) and used consistently. It won’t directly make tendons stronger overnight, but it can help build a more robust structure over time, which is particularly valuable if you’re managing chronic issues or training at high volume.

When it comes to muscle growth or post-training recovery, Collagen doesn’t stack up against high-quality proteins like whey. It lacks the amino acid profile needed to drive muscle protein synthesis, and the evidence for reducing muscle soreness is shaky at best.

So if your goal is long term joint resilience or connective tissue support, collagen may have its place. However, like any supplement, it should complement a balanced diet and solid recovery practices, not replacing the fundamentals.

References

Barclay R, Coad J, Schraders K and Barnes M (2024). Comparing the Effects of Collagen Hydrolysate and Dairy Protein on Recovery from Eccentric Exercise: A Double Blind, Placebo-Controlled Study. Nutrients. 16, 4839.

Inacio, P., Gomes, Y., de Aguiar, A., Lopes-Martins, P., Aimbire, F., Leonardo, P., Sá Filho, A., & Lopes-Martins, R. (2024). The Effects of Collagen Peptides as a Dietary Supplement on Muscle Damage Recovery and Fatigue Responses: An Integrative Review. Nutrients, 16(19), 3403.

Kuwaba K, Kusubata M, Taga Y, Igarashib H, Nakazato K and Mizuno K (2023). Dietary collagen peptides alleviate exercise-induced muscle soreness in healthy middle-aged males: a randomized double-blinded crossover clinical trial. Journal of International Society of Sports Nutrition. 20(1). 2206392

Lee, J., Tang, J., Dutton, J., Dunn, R., Fraser, W., Enright, K., Clark, D., Stewart, C., & Erskine, R. (2023). The Collagen Synthesis Response to an Acute Bout of Resistance Exercise Is Greater when Ingesting 30 g Hydrolyzed Collagen Compared with 15 g and 0 g in Resistance-Trained Young Men. Journal of Nutrition, 154(7), 2076-2086.

Lee, J., Tang, J., Dutton, J., Dunn, R., Fraser, W., Enright, K., Clark, D., Stewart, C., & Erskine, R. (2024). The Collagen Synthesis Response to an Acute Bout of Resistance Exercise Is Greater when Ingesting 30 g Hydrolyzed Collagen Compared with 15 g and 0 g in Resistance-Trained Young Men. Journal of Nutrition, 154(7), 2076-2086.

McKendry, J., Lowisz, C., Nanthakumar, A., MacDonald, M., Lim, C., Currier, B., & Phillips, D. (2024). The effects of whey, pea, and collagen protein supplementation beyond the recommended dietary allowance on integrated myofibrillar protein synthetic rates in older males: a randomized controlled trial. American Journal of Clinical Nutrition, 120(1), 34-36.

Nulty, C., Phelan, K., & Erskine, R. (2025). Hydrolysed Collagen Supplementation Enhances Patellar Tendon Adaptations to 12 Weeks’ Resistance Training in Middle-Aged Men. European Journal of Sport Science, 25(4), e12281.

Nulty, C., Tang, J., Dutton, J., Dunn, R., Fraser, W., Enright, K., Stewart, C., & Erskine, R. (2024). Hydrolyzed collagen supplementation prior to resistance exercise augments collagen synthesis in a dose-response manner in resistance-trained, middle-aged men. American Journal of Physiology-Endocrinology and Metabolism, 327(5), E668-E677.

Oikawa, S., Kamal, M., Webb, E., McGlory, C., Baker, S., & Phillips, S. (2020). Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial. American Journal of Clinical Nutrition, 111(3), 708-718.

Shoulders, M., & Raines, R. (2009). Collagen structure and stability. Annual Review of Biochemistry, 78, 929-958.