Hello Runner,
Welcome back to your weekly moment of endurance nutrition!
Happy Weekend!
How are you?
I'm fine. I'm keeping up with my workouts, work, and studies. But since everyone here in Barcelona is on vacation, it feels like everything is moving at a slower pace. It's strange.
This week I swam in my gym’s pool for the first time. I hadn’t swum since I was 8 years old. Actually, I’ve never liked swimming. My mom enrolled me in swimming lessons, but I was always terrible at it and came in last in every competition among the kids, hahahah.
Since it was my first time, I swam for 20 minutes and was already tired. But I also went to the pool after an hour on the bike, so the fatigue was understandable.
Despite the fatigue, I loved it. It’s great cardio, it’s relaxing, it’s low-impact, it helps beat the heat, and it’s a way to let your body recover.
I don’t know if it’ll become part of my workout routine, but I’ll definitely be going back to the pool.
Today's topic is collagen. But not for skin and hair or building muscles (which it doesn’t); rather, tendon collagen synthesis and tendon adaptation when it is combined with appropriate mechanical loading.
Collagen is constantly being promoted in the wellness world. And these days, it’s found in drinks, vitamins, chocolates, and so on.
In fact, there are plenty of products that claim to be “high in protein,” but when you read the label, you’ll see that the protein used is collagen, not protein powder.
But this is where most runners are mistaken. Collagen should not be confused with whey protein. And it is not the best choice if your primary goal is building muscle.
Let me explain it better.
What is collagen?
Collagen is the body's main structural protein. It makes up much of our tendons, ligaments, cartilage, bone, skin, and other connective tissues. Tendons and ligaments are particularly rich in type I collagen, which gives them strength and helps transmit forces between muscles and bones.
Collagen peptides and whey protein are both proteins, but they have very different amino-acid profiles.
Collagen is rich in glycine, proline, and hydroxyproline, amino acids abundant in connective tissue, but contains relatively little leucine and fewer essential amino acids.
Whey protein, in contrast, is rich in essential amino acids and particularly leucine, making it highly effective at stimulating muscle protein synthesis.
How could collagen help tendons?
Tendons adapt to mechanical loading. When you run, strength train, or perform rehabilitation exercises, your tendons receive a signal to remodel.
Collagen provides amino acids and collagen-derived peptides that can contribute to this remodeling process. Research suggests that consuming collagen or gelatin before exercise can increase markers of collagen synthesis, particularly when the tissue is subsequently loaded.
This is why the combination is interesting:
Collagen + vitamin C + mechanical loading → potentially greater collagen remodeling and tendon adaptation.
Importantly, collagen is not a magic treatment for an injured tendon. Progressive rehabilitation and appropriate load management remain the foundation of tendon recovery.
STRATEGY
The Evidence-based Collagen Protocol
Here’s a good strategy to maximise collagen synthesis for joint and tendon resilience.
Dosage: 15g to 20g.
Always pair with vitamin C (50 mg)
A kiwi, orange, berries, peppers, or another vitamin-C-rich food can accompany your collagen. You don't need to buy a vitamin C supplement
Timing: 30 to 60 minutes before workout
The idea is to have collagen-derived amino acids and peptides available when the tendon receives the mechanical stimulus.
That could mean taking it before:
a strength session
tendon rehabilitation exercises
plyometric training
another appropriately prescribed loading session.
What collagen does not do?
It is not a muscle builder: collagen is an incomplete protein (lacking tryptophan and low essential amino acids). It should complement, not replace, high-quality daily protein sources like meat, fish, chicken, whey, or soy used for muscle repair
It cannot replace load management: collagen provides raw building blocks, but it cannot override poor training programming, inadequate rest, or excessive overuse injuries.
For runners, collagen may be a useful nutritional tool when the goal is supporting tendons, ligaments and other connective tissues rather than building muscle.
If you're recovering from a tendon or ligament injury, collagen may complement a well-designed rehabilitation programme, but progressive loading, appropriate recovery and adequate overall nutrition remain much more important.
And if your primary goal is muscle hypertrophy, choose a high-quality, leucine-rich protein such as whey instead.
Product of the Week
This week's Product of the Week is the HSN Marine Collagen Peptides Powder
Since we’re on the topic of collagen, I’d like to share this product from HSN.
I’ve mentioned products from this brand here in the newsletter before. I’ve always liked their quality.
I found this pure collagen powder that can be added to various drinks. You can make juice with a citrus fruit and add the collagen. That way, you’re getting vitamin C at the same time.
Just pay attention to the dosage. It looks like the scoop that comes with this product dispenses 2 g of collagen. And the recommended dose is 15–20 g.
I found other options in capsule form with the correct dosage, but they come with other active ingredients and nutrients mixed in.
Scientific References
Buchalski et al. (2026). Collagen Supplementation on Tendon-Related Structural and Performance Outcomes: A Systematic Review. Journal of Functional Morphology and Kinesiology. Link
Rogozińska et al. (2026). Synergistic Effects of Collagen Peptides and Vitamin C Supplementation in Tendinopathy Rehabilitation: A Critical Review. Quality in Sport. Link
Lee & Kim (2026). Rehabilitation Nutrition for Tendon and Ligament Injuries: From Collagen Remodeling to Return-to-Activity and Sport. Healthcare. Link
Nulty et al. (2025). Hydrolysed Collagen Supplementation Enhances Patellar Tendon Adaptations to 12 Weeks' Resistance Training in Middle-Aged Men. European Journal of Sport Science. Link
Nulty et al. (2024). Hydrolyzed collagen supplementation prior to resistance exercise augments collagen synthesis in a dose-response manner. American Journal of Physiology-Endocrinology and Metabolism. Link
Bischof et al. (2024). Impact of Collagen Peptide Supplementation in Combination with Long-Term Physical Training on Strength, Musculotendinous Remodeling, Functional Recovery and Other Outcomes. Sports Medicine. Link
Shaw et al. (2017). Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. American Journal of Clinical Nutrition, 105(1), 136–143.
Alcock, Shaw & Burke (2019). Bone broth unlikely to provide reliable concentrations of collagen precursors compared with supplemental sources of collagen used in collagen research. International Journal of Sport Nutrition and Exercise Metabolism, 29(3), 265–272. Link
Jahan-Mihan et al. (2025). Current perspectives on protein supplementation in athletes. Nutrients. Link
Brueckheimer et al. (2025). The effects of type I collagen hydrolysate supplementation on bones, muscles, and joints: a systematic review. Link
Track of the Week 🎧️
This week's Track of the Week is a remix of an old song that I discovered this week. It's perfect for listening to on early morning runs when the sun has already risen.
I’ve chosen Sunshine (My Girl) by Wuki
Any questions or something you would like to share? Drop me an email
Wishing you a great weekend and week ahead!
Here’s to health and good runs⚡️
Ana Paula Alonso