This is a topic that is near and dear to my heart.
I have had pretty much every tendinopathy (also another form of saying tendinitis or tendinosis) under the sun.
The biggest hurdle I had was patellar tendinopathy that caused pain for multiple years and legitimately should have had me questioning whether or not I would ever be able to play basketball again without pain, and whether this would also impact my powerlifting training forever.
One of the biggest factors that helped me was my positivity and confidence. Even after two years of daily pain, being told surgery was likely needed (with a low success rate), and hearing some physiotherapists say I might never be pain-free and would only be able to manage load, I still truly believed I would find a solution.
Combining the above with the fact that I am a dietitian, specialising in sports nutrition, I have gone pretty far down the rabbit hole. I think it is near the point that very few people would know more about nutrition for tendinopathy than I do due to this personal interest. So, I would like to share a few things that could be helpful.
Training/Rehab
Although this is a post about nutrition, if your rehab, training or competing is setting you back week after week, nutrition is not going to solve it.
Common issues with tendinopathy are that people either under-load their tendons, or they over-load their tendons.
You can’t simply rest a tendon that has been problematic for several months. Doing so will only reduce its ability to tolerate load as it becomes weaker.
But at the other end of the spectrum, if you keep loading it to the point that you exceed a 4/10 level of pain OR you are experiencing a noticeable increase in symptoms 24-48 hours post-exercise, you are very likely to be making the issue worse.
The longer the issue persists, the longer recovery is likely to take, even once you find the right approach.
For me, I have had times where I was convinced that I was not far off finding the sweet spot to get to the point where I would be able to transition basketball and powerlifting from being something that was making the issues worse, to something that was a positive stimulus to allow the tendon’s load tolerance to improve.
I would be convinced that adding another supplement, changing diet slightly, getting more/better sleep, adding another training variable or something small like that would make a difference.
Yet when I finally did find that sweet spot, I realised the reduction in loading I needed was more significant than I expected.
I’m adding this caution because, yes, all the information below will help. However, if you’re constantly pushing the tendon beyond its capacity, you’re focusing on the wrong thing.
Calories
The first thing to ask yourself is: Is it easier to grow muscle in a calorie surplus, at maintenance calories, or in a calorie deficit?
That is not a trick question. The higher your calories are, the easier it is to grow muscle.
am not asking that question specifically to talk about muscle, although muscular atrophy around the site of the tendon is common and needs to be addressed for successful rehab. Arguably, improving muscle strength in certain areas could also help take the load off the tendon in question.
I am setting this up to highlight that if you want your tendon to adapt and grow stronger, it makes sense that it will be easier to do with higher calories.
Personally, I think it is silly to strive for a calorie surplus for an extended period of time when you are unable to train effectively though.
Maintenance calories likely makes sense. It is a balance between helping to speed up rehab, while also trying to prevent fat gain.
For lower body tendinopathies, you might question whether weight loss would be beneficial.
With patellar tendinopathy, the research is mixed. I would say it is leaning slightly in favour of those with lower body weight being less likely to get it.
Waist circumference seems to be more relevant than BMI. This could partly be because muscle mass is helpful for preventing tendinopathies, or it potentially is related to inflammatory processes that occurs with higher levels of body fat.
I am not 100% sold on that latter aspect, but it is something that I still consider to be a relevant possibility worth addressing.
People often overlook inflammation in tendinopathy and focus more on the degeneration aspect. The term “tendinopathy” was specifically chosen over “tendinitis” to emphasise that it’s not primarily an inflammatory condition. However, that doesn’t mean inflammation plays no role. This still could be a contributing factor.
The first thing that jumps to most people’s minds are stats like “every kg you lose contributes to the equivalent of a 4kg reduction of the pressure on your knee” which also would have a level of carryover to other lower body tendinopathies.
From one perspective you can make an argument that being in a calorie deficit and dropping weight COULD help a little bit.
I do not have strong advice on this one. Personally, when I decided to drop powerlifting and focus more exclusively on rehab, I also decided to drop from 94kg to <80kg, with the first part of the cut being relatively quick. If you would benefit from being leaner, it could make sense to do that.
My thoughts are:
- There are no real rules but recovery is often quicker at higher calories.
- If you truly believe you are within a couple of weeks of overcoming the issue, it makes sense to eat at maintenance calories.
- If you are particularly far away from being pain-free, and you have excess body fat to lose, you could make an argument for getting leaner. But keep in mind this can slow down progress in terms of strengthening the tendon.
Collagen/Gelatin + Vitamin C
While the research on collagen seems pretty mixed, when you account for a few variables, it actually looks overwhelmingly positive.
It is early days for the research, so I am happy to change my mind on this one down the line. But for now, it is my main recommendation. If you get nothing else out of this article, pay attention to this section.
The variables to account for are:
- Dosage – the sweet spot seems to be 15g+. Lower dosages seem to have less of a positive impact.
- Timing – ideally timing the collagen 40-60 minutes before you rehab/training session allows the amino-acids and collagen peptides to peak in your blood, as blood is flowing through the tendons.
- Vitamin C – this is necessary for collagen synthesis. Therefore, if you were to take a collagen supplement, but had not consumed any vitamin C for a long time, collagen synthesis in the body would not be occurring.
Collagen synthesis in the injured area significantly increases after supplementation has been used in this fashion.
There are also arguments to be made that you can rehab tendons multiple times per day, with shorter bursts, so that total volume still comes outmatched. And by doing that, you can have the collagen supplement multiple times per day as well. This is not an approach I have personally tried, but theoretically, it could dramatically speed up the rehab process.
For more details on collagen supplementation, I strongly recommend reading my far more in-depth article on the topic.
Protein
One argument against collagen supplementation that some people have is that after consumption, it mostly breaks down into amino acids. My understanding is that ~10% remain intact as collagen peptides.
The argument is that if your protein intake is high enough, it should cover this. Similarly to why BCAAs are not effective for muscle growth when total protein is already high.
And there is a grain of truth in this. For overall recovery, it is a good idea to keep protein relatively high. It will also help with muscle retention/gain throughout the rehab process too.
But collagen is specifically high in certain amino acids, such as glycine, lysine and arginine. These amino acids are not great for muscle protein synthesis. Protein sources that are good for muscle protein synthesis are often low in these amino acids.
Basically, collagen protein has a far different ratio of amino acids to almost all other sources.
My advice is to do both. Emphasise protein in general AND also strategically use collagen/gelatin supplementation.
Omega 3
Omega 3 fatty acids might be beneficial for tendinopathy.
They can have a positive impact from an inflammatory perspective.
With omega 3s, I firstly encourage aiming to get them through food. This means focusing on foods like oily fish, walnuts, chia seeds and flaxseeds.
When it comes to research on supplemental forms, one study involving 1.5g of EPA and 1g of DHA showed slightly better outcomes than placebo for rotator cuff tendinopathy.
Another study highlighted that patients with rotator cuff tears have lower omega 3 status than those with no form of rotator cuff tendinopathy.
Overall, it does not seem like overwhelmingly positive evidence that omega 3s are going to make a world of difference. But it is enough that I would be ensuring that you either have a diet rich in omega 3s or supplement if necessary.
Glucosamine and Chondroitin
Glucosamine and chondroitin are often considered more beneficial for osteoarthritis.
Even with arthritis the research and opinions are relatively hit-and-miss. I view them as a 1-3% kind of boost. They likely help, but also probably do not help enough that you notice them.
Beyond osteoarthritis, they could have benefits for tendons.
An in vitro study showed an increase in collagen synthesis of 22% in tendons and 69% ligaments when glucosamine and chondroitin were utilised.
Another study on tendon healing in mice showed better organisation of collagen fascicles, less inflammation and greater collagen synthesis.
Research on rabbits has shown quicker healing following tendon rupture with glucosamine supplementation.
Animal research is often criticised for not always translating well to humans, so I’d advise against overinterpreting these findings. In my view, glucosamine and chondroitin likely won’t cause harm, and they may offer some slight benefits. If you have extra money and are open to trying something that could offer a small improvement, it might be worth considering.
Curcumin
Similarly, to above, the evidence supporting curcumin comes from animal research.
For context, it is actually quite hard to study nutrition for tendons in humans in the real world.
One grim reason is that in animal studies researchers physically examine the tendon at the end of the study. I do not want to go into more detail, but you can imagine why that does not happen in human studies.
The other factor is that although we care about practical outcomes like no longer feeling pain or improved performance outcomes, that is hard in a real-world setting too.
My logic behind saying that is that if say I am capable of loading my tendon with X volume and intensity in training without pain when I add a useful supplement, it is now capable of more.
Say I was previously loading to exactly X volume and intensity, and the supplement increases my capacity by 20%, I would probably change my training to load my tendon to X + 20% as well.
Therefore, things that reduce pain, probably also adjust other variables too.
This is also super important to factor in with all these nutritional variables.
Moving back to curcumin, a study on mice highlighted it improved organisation of collagen fibres and biomechanical properties after a patellar ligament injury.
Another study highlighted improved healing in rats with surgically repaired Achilles tendons.
While curcumin is often thought of for its anti-inflammatory properties, I wanted to highlight that this research literally showed improved healing, not just reduced inflammation.
Once again, this is animal data, not human data. I do not have super high expectations. But if you are desperate, it is also worth a look.
Nitric Oxide – Arginine, Citrulline and Beetroot Juice
Three things that got me interested in blood flow for tendons are that:
- If you get an ultrasound of a long-lasting tendinopathy, the pathology has changed to allow for increased blood flow. Tendons traditionally get far less blood flow than muscles, but this is increased in tendinopathy as one of the body’s mechanisms for trying to heal itself.
- Nitroglycerin patches that promote blood flow have some evidence that they can help reduce pain associated with tendinopathy and improve healing. It is not strong evidence that it helps with all tendinopathies, but it is theoretically sound. I also think the lack of consensus is more to do with training volume changes associated with reduced pain, leading to flare-ups again down the line anyway.
- Collagen supplementation appears to be more effective when blood flow goes to the injured area. If we can increase that blood flow during training (or maybe even just in general) this could carry-over to improved outcomes.
An in-vitro study using L-arginine, increasing nitric oxide production, enhanced collagen synthesis in human tenocytes.
In animal studies, nitric oxide inhibitors have been found to reduce tendon healing, while addition of nitric oxide has improved healing.
Using knowledge from sports nutrition, we know that l-citrulline works better for increasing arginine levels than arginine supplementation does. We also know that beetroot juice works well for improving nitric oxide and blood flow as well.
Overall, this is one of my hotter takes to a certain degree. It’s not an island I’m willing to die on. Particularly because there is no context. There is nothing like “500ml of beetroot juice per day reduced tendinopathy-related pain by 30% over a specific timeframe.”
Another relevant aspect though is that some people have had severe tendinopathy for so long that they haven’t gotten a “pump” in the surrounding muscles for a very long time. Potentially even finding ways to achieve that pump, without causing pain, could help.
A combination of beetroot juice or another nitric oxide promoter, with some form of training that does not cause pain but promotes blood flow to the area, could theoretically help to speed up the rate of healing.
Vitamin D
Vitamin D is not talked about much when it comes to tendons. My take is that if you are on the low end of the healthy range, or are deficient when you get a blood test, it is worth supplementing. Alternatively, getting more sun.
This is a pretty safe recommendation because even if it does not help your tendons, it will help other stuff.
A deficiency in vitamin D could be a limiting factor in collagen synthesis and also cause increased oxidative stress.
Vitamin D deficiency is relatively common as well, so this is worth considering too.
Another aspect to consider is that 80% of people undergoing surgical repair of the rotator cuff in one study were vitamin D deficient. That’s a mind-blowing stat.
This is an easy one. If you have suspicions of vitamin D deficiency or just low levels, get a blood test and check. Or if you are in a country where this is harder or costs money (we are fortunate that it is free in Australia if you see a bulk-billing GP) then maybe just jump straight to supplementation.
Without further context, I would recommend 1000-4000IU per day. For larger deficiencies, I would go significantly higher, but I am not comfortable writing that without context in a blog.
Other Health Conditions
This is less interesting to me but worth mentioning.
Gout, high cholesterol and diabetes are risk factors for tendinopathy too.
They directly impact tendon function and pathology. Some medications impact it too.
If they are issues, it is worth addressing the management of those conditions too, which could improve recovery of tendinopathy as well.
Summary
From one perspective, none of these things are absolute game changers beyond nailing the fundamentals.
But I also do not want to undersell the importance of some of these things either. I think a lot also depends on the overall protocol used.
For example, one NBA player who was utilising a stress-relaxation protocol of heavy isometrics, 40-60 minutes after consuming the collagen protocol discussed earlier, 2x per week, completely healed his patellar tendinopathy.
This is borderline unheard of. Most experts talk about “treating the doughnut, not the hole” as in basically saying the damaged area is untreatable and we are just focusing on strengthening the healthy tendon surrounding it.
But this protocol had MRI proof the “hole” was treated. The logic was that the stress-relaxation protocol allowed the injured area to reduce the stress shielding and start to bear some load again. And the targeted nutrition protocol then provided the tools for the area to heal.
This is even more fascinating to me because we are just scratching the surface of optimising protocols for tendinopathy rehab, from my perspective. We have tools that we know typically work. But I also think there are tonnes of stones left unturned, in practice, from what I can see.
Combining these nutritional strategies with effective rehab can accelerate tendinopathy recovery much faster than usual. However, my final piece of advice is not to rush the process. From what I have observed, those with longer recovery times are often the ones who push themselves too hard, too quickly. Patience is essential.
