Achilles Tendinopathy in Runners: What the Research Says About Fixing It (And What's Changed)

If you've dealt with Achilles pain as a runner, you've probably already googled your way to the same answer everyone gets: eccentric calf raises off the edge of a step. Three sets, fifteen reps, twice a day, heel dropping slowly below the stair. Maybe you've been doing them for weeks. Maybe months. Maybe you did them, felt a little better, stopped, and the pain came back.

Here's the thing: that protocol isn't wrong. But the research has moved on, and the current evidence says it's no longer the whole answer, and for a lot of runners, it may not even be the best starting point.

I see Achilles tendinopathy in the clinic constantly. It's one of the most common running overuse injuries there is, making up roughly 7 to 9 percent of all running-related injuries, and it has a stubborn reputation for sticking around. The runners who struggle most with it are usually the ones who treat it like an acute injury: rest when it hurts, run when it doesn't, never really address what's driving it. That cycle can go on for years.

Let me break down what the current research actually says, what it means in practical terms, and how to think about this injury differently than most runners do.

What Is Achilles Tendinopathy, Exactly?

This is worth clarifying upfront because terminology matters here.

Tendinopathy is not tendinitis. Tendinitis implies acute inflammation, a fresh injury with an inflammatory response. Achilles tendinopathy, especially the chronic variety that plagues runners, is a degenerative condition. The tendon tissue itself has become disorganized and thickened. There's often a pain response, but it's not primarily driven by inflammation. That distinction changes how you treat it.

The Achilles tendon also has two separate problem zones. Mid-portion tendinopathy sits roughly 2 to 6 centimeters above the heel bone. This is the classic "thickened knot" in the middle of the tendon that hurts when you poke it. Insertional tendinopathy occurs right at the attachment point at the heel bone. These two respond differently to treatment, which is something most generic internet protocols completely ignore.

What the Research Shows

A 2023 systematic review and meta-analysis published in BMC Sports Science, Medicine and Rehabilitation (Prudêncio et al.) pooled data from eight randomized controlled trials comparing eccentric exercise to other exercise approaches for mid-portion Achilles tendinopathy. A separate 2023 systematic review and meta-analysis in Orthopaedic Journal of Sports Medicine (Maetz et al.) compared exercise loading protocols more broadly, including against passive treatments. Combined with the 2024 JOSPT clinical practice guideline update on midportion Achilles tendinopathy, the picture that emerges is fairly consistent:

• Exercise is clearly better than passive treatment (rest, ultrasound, massage alone). If you're waiting for it to heal on its own, the research is not on your side.
• Eccentric exercise is effective, but the evidence that it's superior to other loading approaches has weakened. Heavy slow resistance training, loaded calf raises performed slowly through the full range in both directions, not just the lowering phase, has shown comparable or better outcomes in several trials.
• Heavy slow resistance training (HSR) is likely the most practical and well-tolerated approach for recreational runners. It builds tendon capacity in both the eccentric and concentric phases, doesn't require a staircase, and is easier to load progressively over time.
• Insertional tendinopathy responds differently. For runners with pain right at the heel bone, the classic below-the-step eccentric drop actually loads the tendon in a position that can compress it against the heel bone and make symptoms worse. Insertional cases generally do better with range of motion limited to neutral, no deep drop below the step.
• Minimum effective program length is 12 weeks. This is longer than most runners expect. Tendons are slow-adapting tissue. Eight weeks is often not enough. Studies showing the best outcomes run 12 weeks or longer.
• Running doesn't have to stop entirely, but it needs to be managed. Complete rest often leads to deconditioning without meaningfully accelerating tendon recovery. A graded approach, reducing volume and intensity, then building back while loading in the gym, is better supported than full stoppage.

What This Means If You're Dealing With This Right Now

The most common pattern I see in the clinic is this: a runner comes in, they've had Achilles pain for three to six months, they've been doing bodyweight heel drops, they feel about the same or a little worse. When I ask about their training, they've either kept running the same volume and intensity, essentially ignoring it, or they've stopped entirely and lost a lot of fitness waiting for it to resolve.

Neither approach is working because neither addresses the actual problem.

Achilles tendinopathy in runners is almost always a tendon capacity issue. The tendon isn't strong enough, stiff enough, or resilient enough to handle the loads being placed on it. You don't fix that with rest. You fix it with progressive loading that gradually builds the tendon's capacity above the threshold that's currently exceeding it.

From a PT standpoint, what's happening is that the tendon tissue has responded to overload by remodeling in a disorganized way. The collagen structure gets disrupted. The tendon swells, thickens, and becomes less efficient at storing and returning energy, which is exactly the job it needs to do thousands of times per mile. Loading it progressively tells the tendon to reorganize and adapt. Rest doesn't give it that signal.

The other thing I have to address often is the 12-week timeline. Runners hear "12 weeks" and immediately want to compress it, skip steps, or abandon the program the moment symptoms ease up at week 6. That early symptom relief is not the same as tissue recovery. The tendon can feel better weeks before it's actually rebuilt its capacity. This is why so many runners get 60 to 70 percent better, go back to full training, and end up right back where they started.

How To Apply It

Step 1: Figure out which type you have.

Press on your Achilles tendon. If the sore spot is in the middle of the tendon, a few centimeters above the heel, that's mid-portion. If it's right at the bump where the tendon meets the heel bone, that's insertional. The treatment is different, so this matters.

Step 2: Start with heavy slow resistance (HSR) calf raises.

For mid-portion: stand flat on the floor (or on a flat surface, no step drop needed), with enough load that 15 slow reps is genuinely hard. Slow means 3 seconds up, 3 seconds down. Start with bodyweight if needed, but progress the load every week or two. Three sets, twice a day if possible, or at minimum once daily.

For insertional: same approach, but keep your heel at or above neutral. No dropping below the step. The position of end-range dorsiflexion is what compresses the tendon against the calcaneus. You want to avoid that.

Step 3: Treat load management as seriously as the exercise program.

Running doesn't need to stop, but it does need to be honest. A rule I use with athletes: if pain during a run stays at a 3 out of 10 or below, and doesn't worsen after, that's manageable. If it's climbing above a 5 during the run, or you're sore for more than 24 hours after, that's feedback that you're exceeding what the tendon can currently handle. Reduce duration and intensity, not necessarily frequency.

Step 4: Add isometric holds for acute pain flares.

When the tendon is highly irritable, with significant morning stiffness, pain with the first few steps, or significant soreness the day after runs, isometric calf holds can help calm the pain response without adding the cyclic loading of a full rep. Standing calf raise held at the top for 30 to 45 seconds, five sets. This won't build tendon capacity the way HSR will, but it can manage symptoms well enough to let you start the real work.

Step 5: Be patient at 12 weeks, not 6.

Set the expectation upfront that you're working on a 12-week timeline minimum. Track your symptoms weekly, not daily. Daily variation will drive you crazy. Look for the trend. By 8 weeks you should be significantly better. By 12 weeks you should be able to resume normal training load. If you're not improving by week 8, that's the right time to see someone.

A Note on What Doesn't Have Strong Evidence

A few things runners commonly turn to that the research doesn't strongly support:

Stretching the calf before or after runs has not consistently shown a benefit for Achilles tendinopathy. Static stretching a tendon that's already overloaded and sensitive can sometimes make symptoms worse in the short term. Stretching isn't harmful, but it shouldn't be your primary treatment.

Foam rolling the Achilles is a waste of time. You can't roll out a tendon the way you can a muscle belly. The Achilles has almost no contractile tissue. Save the foam roller for your calves and quads.

PRP injections and shockwave therapy both have some evidence, but the evidence is weaker and more mixed than their popularity would suggest. They're reasonable options to discuss with a PT or sports medicine physician if conservative loading hasn't worked at 12 to 16 weeks, not before.

The Bottom Line

Achilles tendinopathy is a capacity problem, not a rest problem. The research consistently points toward progressive loading as the primary treatment, the timeline is longer than most runners want to accept, and the specific protocol matters more than most generic advice suggests, especially if your pain is at the insertion rather than mid-tendon.

If you've been doing the same bodyweight heel drops for weeks with no real change, you're not doing the wrong thing. You're just not doing enough. Add load, slow it down, give it time.

Hit reply or leave a comment: what does your current Achilles management look like, and how long have you been dealing with it? I read all of them.

Keep running happy, healthy, and strong, Spencer

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