Does collagen help runners?
Probably, for the tissues that take the most punishment when you run: tendons, ligaments and the collagen framework inside bone. It will not make you faster on its own and it will not fix a training error, but the trial evidence for collagen and tendon health in active people is stronger than most runners assume, and the protocol is cheap to follow. The Achilles, the patellar tendon, the plantar fascia and the joint capsules are almost entirely type I collagen, and they adapt to training far more slowly than muscle, which is why the classic running injuries are connective-tissue injuries rather than muscle tears. This page sets out what running does to that tissue, what dose and timing the research actually used, what the trials found (including the one that found nothing) and how a 20g ready-to-drink sachet fits into a runner's week.
What running does to connective tissue
Every stride loads the Achilles tendon with several times bodyweight, and the plantar fascia stretches and recoils with it. Over a 60 km week that is tens of thousands of loading cycles through the same few centimetres of tissue. Muscle can rebuild in 48 hours; tendon collagen turns over far more slowly, and its blood supply is poor, so it accumulates load faster than it repairs. That mismatch is why the injuries runners know by name are almost all tendon and bone: Achilles tendinopathy, patellar tendinopathy (runner's knee at the front), plantar fasciitis (that first-step heel pain in the morning), medial tibial stress syndrome (shin splints) and, at the far end, tibial and metatarsal stress fractures.
Two things make runners a special case. The load is repetitive and one-directional, so a small structural weakness gets hit the same way thousands of times. And most runners eat little dietary collagen: the gelatinous cuts, skin and bone broth that used to supply glycine, proline and hydroxyproline are rare in a modern diet. Supplementing hydrolysed collagen puts those building blocks in the bloodstream at the moment the tendon is being loaded, which is the mechanism the pre-loading studies below rely on.
Bone matters too. Roughly a third of bone by weight is collagen, and running is weight-bearing, so it is good for bone density, yet high-mileage runners (particularly those with low energy availability) still see stress-related bone injuries. Collagen is not a treatment for any of that, but it is part of the raw material.
The protocol: dose and timing for runners
The research protocol is simple and has been consistent since 2017: take a meaningful dose of hydrolysed collagen or gelatin with vitamin C about an hour before the session that loads the tissue you care about. Blood amino acid levels peak around 60 minutes after ingestion, so the tendon is being loaded while glycine and proline are at their highest. On rest days a smaller daily dose keeps intake consistent.
| When | How much | Why |
|---|
| 30–60 min before a hard run, hills, plyometrics or strength work | 15–20g hydrolysed collagen with vitamin C | Shaw 2017 pre-loading window; Lee 2023 shows more is better up to 30g |
| Easy days and rest days | 5–10g | The dose used in the 6- to 12-month tendon and joint trials |
| Minimum commitment | 8–12 weeks, then reassess | Tendon adapts slowly; the knee-pain and tendon trials ran 12–24 weeks |
| Vitamin C | 50mg or more alongside the dose | Cofactor for the enzymes that cross-link new collagen |
| Creatine (optional) | 3–5g daily | Useful for runners who strength train; not a tendon supplement |
Two notes. Collagen supports loading; it does not replace it, and the Achilles trials with the best results paired it with a progressive eccentric programme. And collagen is not a complete protein, so it sits alongside your post-run whey and your dinner rather than replacing them. See collagen dosage for athletes for the full breakdown.
What the trials show
Pre-loading works in the lab. Shaw 2017 gave healthy young men 15g of gelatin with vitamin C an hour before six minutes of jump-rope exercise. Blood markers of collagen synthesis roughly doubled compared with placebo, and ligaments engineered from their serum were stiffer and contained more collagen. Lee 2023 repeated the idea with 0g, 15g and 30g of gelatin and found a dose-response: 30g raised collagen synthesis markers more than 15g, which raised them more than nothing. This is the basis of the 15–20g pre-session dose.
Tendons adapt over months, not weeks. Praet 2019 followed runners with Achilles tendinopathy for six months on 2.5g of specific collagen peptides a day alongside an eccentric heel-drop programme. The collagen group reported better symptom scores and a better return to running than the placebo group doing the same exercises. Jerger 2022 gave 5g of collagen peptides daily for 14 weeks with a calf-strength programme and measured the Achilles tendon directly: cross-sectional area increased more in the collagen group. Dressler 2018 found 5g a day for six months improved ankle stability in people with chronic ankle instability, which is relevant to trail runners.
Knees and joints. Zdzieblik 2017 gave 5g of collagen peptides daily for 12 weeks to young, active adults with activity-related knee pain and found a greater reduction in pain during activity than placebo. Clark 2008 is the older, larger trial: 10g of collagen hydrolysate daily for 24 weeks in athletes with joint pain, with significant improvements in pain at rest and when walking and lifting. Neither trial is a licence to run through pain, but both used doses a runner can easily match.
Soreness and bone. Clifford 2019 gave 20g of collagen peptides daily for nine days around a damaging bout of drop jumps and found lower muscle soreness at 48 hours compared with placebo. König 2018 gave 5g daily for 12 months to postmenopausal women and found bone mineral density improved at the spine and femoral neck, which is the strongest bone evidence available. Rathleff 2015 is not a collagen study at all: it showed that high-load strength training beat stretching for plantar fasciitis, which is why every protocol on this page says "with loading".
The honest null result. Aussieker 2023 gave 30g of collagen protein immediately after a resistance session and measured muscle connective-tissue protein synthesis over the following hours. It found no increase compared with placebo. That is a real finding and it matters: collagen taken after the session does not appear to switch on connective-tissue synthesis in the way the pre-loading studies suggest it might beforehand, and collagen is not a muscle-building protein. It also tells you where the evidence is thin: the strongest results come from months of use combined with the right exercise.
How KUDU fits a runner's week
The practical problem with the protocol is not the science, it is remembering to mix a 20g scoop of powder into water an hour before a 6 a.m. run. KUDU's 20g Liquid Collagen Protein is a 63ml ready-to-drink sachet: 20,000mg of hydrolysed bovine collagen (type I and III, the types tendon and bone are made of), 85 kcal, 0g sugar, 0g fat, dairy free and gluten free. It lives in the glovebox or the running belt and you drink it in the car park before the session. Four flavours (Sour Cherry, Peach, Orange, Strawberry & Vanilla), made in the UK, and Informed Sport certified, so drug-tested club and county athletes can use it with a batch-tested record.
Runners who also strength train can use the Collagen + Creatine sachet on gym days: 10g hydrolysed collagen, 5g creatine monohydrate and vitamin C in a 44 kcal mix-with-water sachet. A box of 14 is £34.95, from £1.99 a sachet on subscription, and the Sampler Box (£12) is the easiest way to try all four flavours. Every order carries a 60-day money-back guarantee, and the range holds 4.8 stars from over 480 verified reviews.
A runner's weekly collagen plan
| Day type | Collagen | Timing | Notes |
|---|
| Long run or tempo | 20g sachet | 30–60 min before | Pair with 50mg+ vitamin C if the drink does not already include it |
| Hills, intervals, plyometrics | 20g sachet | 30–60 min before | Highest tendon load of the week; do not skip this one |
| Strength and calf work | 20g sachet or C+C sachet | 30–60 min before | C+C adds 5g creatine for the gym session |
| Easy run or rest | Half to one sachet (10–20g) | Any time | Keeps daily intake consistent |
| Race week | 20g daily | Before the last hard session, then mornings | Nothing new on race morning; keep the routine you have practised |
| Return from injury | 20g before every rehab session | 30–60 min before | Follow the physio's loading plan; collagen supports it, it does not replace it |
Runner guides
Collagen for runners: FAQs
Should I take collagen before or after a run?
Before. The pre-loading trials (Shaw 2017, Lee 2023) dosed 30–60 minutes before exercise so that amino acid levels peaked while the tendon was under load, and Aussieker 2023 found that a large dose taken after resistance exercise did not raise connective-tissue protein synthesis. Post-run, prioritise a complete protein and carbohydrate for muscle recovery instead.
Does collagen help shin splints?
There is no trial specifically on medial tibial stress syndrome. The closest evidence is the bone work (König 2018, 5g for 12 months) and the tendon trials, and the honest answer is that shin splints respond first to managing mileage, cadence and footwear and to calf and hip strengthening. Collagen may support the bone and connective tissue that is being overloaded, but it will not offset a 30 per cent jump in weekly volume.
How long before I notice a difference in my Achilles?
The Achilles studies ran 14 weeks (Jerger 2022) and six months (Praet 2019). Expect to give it a full training block, ideally alongside a progressive calf-loading programme, before judging. Most runners notice less morning stiffness before they notice anything else.
Is 20g too much for a runner who only does 20 miles a week?
No. The dose-response work (Lee 2023) went up to 30g with no downside, and 20g is only 85 kcal. Lower-mileage runners can use a full sachet before their hardest session and half a sachet on other days, which still lands inside the 5–10g maintenance range used in the long-term trials.
Can I take collagen on race morning?
Yes, if you have used it before hard sessions in training and it sits well; a 63ml sachet is gentler on the stomach than most gels. The rule is the same as for every race-day decision: nothing new.
Other sports: Hyrox, CrossFit, cyclists, rugby and football, the gym. Browse the full liquid collagen range.
