Could a calcium deficiency be causing my reoccurring injuries?

Hey everyone!

“Long time listener, first time caller”
I feel like there are a lot of cyclists that take supplements to maximize their performance but one thing I’ve noticed that is lacking in my diet and supplements is calcium.

For backstory, I’m a 23 year old college student that is a cat 1 cyclist. I try to eat a healthy diet based on affordability and convenience so that usually means limited types and amounts of fruits and vegetables are eaten daily. I usually only have plant-based milks and don’t eat much cheese or yogurt. I’ve also had problems having a clean season without injury meaning only 1 out of my last 4 years I haven’t had to take extended time off the bike (4+ weeks) to recover. Usually I’ve had knee problems concentrated around the patellar tendon but last year suffered from Achilles tendinitis. I’ve increased stretching and strength training over the years which has helped but doesn’t always work. Foam rolling and active release typically don’t do much to help my tight quads but dry needling does provide relief.

Anyways, circling back, I haven’t had any bloodwork done recently but I realize I don’t typically get the recommended daily amount of calcium. I believe there is also probably a significant loss in calcium from sweat loss as well. I know we usually associate calcium with teeth and bones but I’ve read that it can also affect your squeezing and relaxing of muscles. Does anyone have experience with this?

I take one of these (half dosage) per day:

Bones and tendons are largely built from protein, I’d start there (especially given your emphasis on plants vs animal sourced products). I really doubt calcium intake being lowish would cause the pain your describing. Sweat calcium loss is fairly low. Calcium is part of the muscle contraction process for electrical signal conduction… if that wasn’t working right you’d know. More calcium won’t yield stronger muscles. In fact, tendon strains suggest too much force already. Conversely, magnesium helps your muscle relax.

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I really wouldn’t say I have a plant based diet in the slightest and get plenty of protein. Vegetables were something I’ve been lacking and was recommended to try to increase my intake of from a nutrition consultation so I thought it was of note. The irritation may not be entirely in the tendon but a tight muscle rubbing on the fat pad.

IANA doctor or nutrionist:

What seems more likely to be the cause of your injuries:
a nutrient deficiency delaying or interfering with healing
over training / under-recovery

My guess is the latter is much more likely. Is your sleep dialed in? You can try tracking your sleep and diet for a couple of weeks and see if things are as good/bad as you suspect.


Great points – could well be something non-nutritional. Definitely could just be too much load to recover, or fit issue, shoe, or some other body asymmetry.

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I think I’m getting enough sleep. This was something I thought of previously so I was working on that for the past 10ish months and average 8 hours. I guess it’s possible I need more rest from training but I usually have one day a week completely off the bike. Typical weeks are ~600-650 TSS in 10-12 hours.

You could try some collagen powder. I was having consistent tendonitis issues and about 6 months ago started supplementing with collagen. I have not had any issues since. Listen to this interesting podcast for more info on collagen:

Also I used to be into aggressive stretching, thinking that it would help me, but I actually think too much stretching is a bad thing for some people. I do much better when I dont stretch aggressively.

Also make sure your bike fit is not causing overuse injuries.


If you haven’t heard of it I recommend the book Overcoming Tendonitis by Steven Low. He summarizes all the current research on tendonitis including supplements, modalities, and surgeries and classifies them by the quality of supporting evidence.

@dantok7 I hesitate to mention this because it might not bring any value to this thread…but, unrelated sport (strength training) if jr athletes started to get chronic connective tissue injuries I’d always ask them to up the protein intake. Of course, in addition to what their doctors suggest.

You’re probably already getting enough protein by most metrics. Get 15% more. Just something to think about.