we need to talk about why we're still being given 2005 achilles advice

a few weeks ago, one of the biggest running publications on the internet published a brand new achilles pain guide. it was written in january 2026, medically reviewed, expert-quoted and sounded completely legit.

it told you to ice your heel, stretch your calf off a step every day, foam-roll, stop running, and rest until it stops hurting. it called the condition "achilles tendinitis”.

every single one of those recommendations conflicts with the last 15 years of research 🫠

the doctors in that piece are qualified and mean well. but there is a massive gap between what gets published in a magazine and what the science actually says. when millions of runners are going to follow that advice this year, that gap matters.

this is the guide we wish that article had been.

the name is the first problem.

for years we've been told we have "tendinitis." the "-itis" part means inflammation, like tonsillitis, or appendicitis. things that are genuinely on fire. so it made total sense that every guide told you to ice it, rest it, and take ibuprofen.

except chronic achilles pain is almost never actually inflamed. two researchers, dr. jill cook and dr. ebonie rio, spent years proving that it's a completely different process. the tissue is degrading and not inflamed, and the correct term is tendinopathy (ten-din-op-athy). swapping that one word changes everything about how you treat it.

when a tendon gets overloaded repeatedly, the cells inside it start to malfunction. they produce these water-attracting proteins that pull fluid into the tendon and push the fibres apart. that lump you might feel on the back of your heel? not scar tissue. mostly just fluid trapped in a disorganised structure.

icing it for 20 minutes does nothing for that. you're numbing the area, which feels productive, but the structure isn't changing. some research even suggests taking too many anti-inflammatories can actually block the repair signals your body is trying to send. and full rest? that leads to something called stress shielding, which is basically your tendon getting weaker from not being used. more on that in a sec.

this is the part most articles skip, and it's genuinely important.

there are two different types of achilles tendinopathy and they need completely different treatment. getting this wrong is why so many people stay stuck.

type 1: mid-portion

where: the classic sore spot, about 2–6cm above where the tendon meets the heel. you can pinch it between your fingers.

the vibe: this one actually responds well to movement and loading. it's the more straightforward one to rehab.

type 2: insertional

where: right at the bottom, exactly where the tendon attaches to the heel bone. sometimes feels like a hard bony bump.

the rule: do not stretch your calves if you have this type.

no, really. if you have insertional pain and you've been dropping your heel off a step every morning because that's what every guide says, you've been pressing the sore spot directly into the bone every single day. that's why you're not getting better. you're not doing it wrong, you were just given the wrong advice.

the article we mentioned acknowledges this type exists. it then prescribes the exact same stretching routine for both. that's the problem.

sometimes it's not the tendon at all. a few things that can feel identical:

retrocalcaneal bursitis: there's a small fluid-filled sac (called a bursa) that sits between your tendon and heel bone. when it gets irritated, it feels a lot like insertional tendinopathy. if the back of your heel looks puffy or feels squishy rather than firm, this might be what's going on.

heel bone stress fracture: if your pain keeps getting worse even when you rest, or if squeezing the sides of your heel hurts, this is a stop-everything situation. needs an X-ray or MRI.

nerve irritation: the nerves that run alongside the achilles can get aggravated too. if you feel burning, tingling, or shooting pain down into your foot, the issue might be nerve-related rather than tendon-related.

plantaris irritation: most people don't know this, but you have a tiny extra tendon running right next to your achilles called the plantaris. in some people it rubs against the achilles and causes pain that feels exactly like tendinopathy.

it's not always just about running too much. a few things that can make tendons more vulnerable:

certain antibiotics: some common antibiotics (cipro, levaquin) carry a serious warning because they can actually weaken tendon tissue. if your pain started after a course of antibiotics, mention it to your doctor.

metabolic health: high cholesterol, high blood pressure, and diabetes can all affect tendon quality and increase injury risk.

hormones: for women, dropping oestrogen levels (during perimenopause or menopause especially) can affect how well the body produces collagen, which tendons are largely made of. this is underresearched and undertalked about.

counterintuitive but important: tendons need to be loaded to heal.

the cells inside your tendon can literally sense pressure and movement. that sensation is what tells them to maintain their structure and stay strong. when you stop running completely and rest for weeks, you remove that signal. the tendon reads the silence as: we don't need to be strong anymore. and it starts to deteriorate further.

when you come back from your "rest period," your tendon is actually weaker than when you stopped. this is why the rest-flare-rest cycle never ends.

what you want instead is modified load. enough movement to tell the tendon to repair, not so much that you keep aggravating it.

this one is wild but worth knowing.

with a chronic achilles injury, your brain actually changes how it communicates with your calf muscle. it starts anticipating pain and puts the brakes on your output before you even feel anything. this is called cortical inhibition, which is basically your nervous system being overly cautious. it's why your calf can feel weak or uncoordinated even on days when the pain isn't that bad.

if you skip straight to strengthening exercises, you can't access the muscle properly because the brakes are still on. you have to release them first.

this is where isometrics (exercises where you hold a position without moving) come in. heavy holds have been shown to reduce that overprotective response and actually act as a painkiller. the relief can last up to 45 minutes, and unlike actual painkillers, they're also rehabbing the tissue at the same time.

heads up: this is educational, not a prescription. work with a physio who knows tendinopathy for your specific plan.

the evidence points to four phases of rehab. the rest-flare-rest cycle almost always happens because someone skipped one.

phase 1: isometrics (the painkiller)

the goal here is to calm the nervous system down and get the muscle firing properly again. a calf raise hold works well: rise onto your toes with some weight, hold for 45 seconds, repeat 5 times. if you have insertional pain, keep your heel flat (no step).

phase 2: heavy slow resistance (the builder)

now you're actually remodelling the tendon tissue. a weighted heel raise with a slow, controlled tempo (3 seconds up, 3 seconds down) at a weight that makes 8–10 reps genuinely hard. this phase takes longer than you think it will. that's normal.

phase 3: energy storage (the spring)

a healthy tendon acts like a spring. it stores and releases energy with every stride. once your strength is solid you need to retrain that. think pogo hops, skipping, box jumps, starting with two feet before going to one. running usually shouldn't come back until these feel good.

phase 4: return to run (the 24-hour rule)

some discomfort while running (a 3 out of 10 max) is okay. the real check is the next morning: is your stiffness worse than yesterday? if yes, you did a bit too much. if the same or better, keep going if your physio says so. it’s a simple system that works and takes the guesswork out completely.

if your physio or doctor says any of the following, you are allowed to find someone else.

🚩 "you need complete rest." rest makes tendons weaker. unless you have a rupture, modified load beats no load every time.

🚩 the whole session is passive treatment. massage, ultrasound, laser and cupping cause zero change in the tissue structure. if there's no loading involved, you're probably not making progress.

🚩 they give the same advice regardless of where your pain is. if they prescribe heel drops off a step without asking exactly where it hurts first, they're missing the most critical distinction in this whole injury.

🚩 they call it tendinitis. outdated term usually means outdated treatment.

🚩 they offer a cortisone injection early. cortisone can mute pain for a few weeks but it's been shown to break down tissue quality over time. long-term, people who skip the injection and just do the rehab tend to do significantly better. it should be an absolute last resort, not a first option.

an achilles injury is almost always a load management problem. and load management is one of the most fixable things in sports medicine. it just takes patience and the right information, which, as we've established, is not always easy to find.

—xx, athletegirl

scientist credit

cook, j.l. & purdam, c.r. (2009). british journal of sports medicine, 43(6), 409–416 · cook, j.l. & purdam, c.r. (2012). british journal of sports medicine, 46(3), 163–168 · coombes, b.k., bisset, l. & vicenzino, b. (2010). the lancet, 376(9754), 1751–1767 · dean, b.j.f. et al. (2014). seminars in arthritis and rheumatism, 43(4), 570–576 · khan, k.m. & scott, a. (2009). british journal of sports medicine, 43(4), 247–252 · kongsgaard, m. et al. (2009). scandinavian journal of medicine & science in sports, 19(6), 790–802 · magnusson, s.p., langberg, h. & kjaer, m. (2010). nature reviews rheumatology, 6(5), 262–268 · malliaras, p. et al. (2013). sports medicine, 43(4), 267–286 · rio, e. et al. (2015). british journal of sports medicine, 49(19), 1277–1283 · silbernagel, k.g. et al. (2007). american journal of sports medicine, 35(6), 897–906 · tsai, w.c. et al. (2004). connective tissue research, 45(3), 152–158