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Eccentric heel drop

Also called heel drop, eccentric heel-drop, eccentric calf exercise

A calf exercise built around lowering the heel. What studies measured it loading in the Achilles tendon and calf muscles, how knee angle changes the picture, and what one session does to the tendon.

Region
Lower leg
Muscles
gastrocnemius, soleus
Updated
October 23, 2026
Reviewed
October 23, 2026 · how entries are checked

Movement

Lowering and raising

The calf muscles at the back of the lower leg mainly produce plantar flexion, which means pointing the foot down1. Dorsiflexion means pulling the foot and toes up toward the shin. In the heel drop as Alfredson and colleagues described it, the person starts on tiptoe with the ankle fully plantar flexed2. They lower the heel under control until the ankle reaches full dorsiflexion2. This lowering loads the calf eccentrically2.

Eccentric work is muscle work done while the muscle lengthens, as when lowering a weight slowly. To rise again, the person moves their weight onto the other leg, so the working leg only lowers2. Concentric work is muscle work done while the muscle shortens.

Knee straight and knee bent

In the original description, the exercise is done both with the knee straight and with it bent2,11. The gastrocnemius is the large calf muscle nearest the skin, and the soleus is a wide, flat calf muscle beneath it. The bent-knee version is meant to change how the load is shared between them2. The idea is that a bent knee leaves the gastrocnemius shorter and less active2. Whether the gastrocnemius is less active is where the studies below disagree2,6.

What it loads

The Achilles tendon

The calf muscles nearest the skin end in the Achilles tendon, which attaches to the calcaneus (heel bone)1. A tendon passes force from a working muscle to the bone, and that pull moves the body12.

One modelling study, which estimates forces inside the body with a model, looked at 19 healthy adults doing the heel drop barefoot2. It estimated peak Achilles tendon force at each knee angle2:

Estimated peak Achilles tendon forceKnee straight3.0 times body weightKnee bent2.9 times body weight
Estimated peak Achilles tendon force (times body weight). Bars start at zero; the table below gives each value with its source.
Heel drop versionEstimated peak Achilles tendon force
Knee straightAbout 3.0 times body weight2
Knee bentAbout 2.9 times body weight2

In that group, bending the knee did not change peak Achilles load2. Peak ankle moment, the turning effect of force around the ankle, was lower with the knee bent2.

What changed the load

In 21 healthy men, estimated Achilles loading was lowest in seated heel raising and lowering, and highest on one leg13. Loading was greater for any part done on one leg13. That included lowering on one leg after raising on two13.

In 18 healthy people, two things predicted peak Achilles tendon force, both standing and seated4. One was the extra weight carried, and the other was how far the ankle went into dorsiflexion4. With the same extra weight, tendon force was larger in the bent-knee heel drop than in straight-knee heavy slow resistance, a slow, heavy calf exercise4. The authors put this down to the greater ankle dorsiflexion angle in the heel drop4.

For comparison, another study of eight healthy young adults estimated peak Achilles load across a set of exercises14. It ranged from 0.5 times body weight in a seated heel raise to 7.3 times in a forward hop on one leg14.

Lowering compared with raising

Three studies of healthy people found no extra tendon force in lowering, or in eccentric exercises3,4,5:

  • In 16 people on one leg, Achilles tendon loads did not differ between lowering and raising3.
  • In 18 people, estimated tendon force was not larger in lowering than in raising4.
  • In seven people, peak tendon force and change in tendon length did not differ significantly between eccentric and concentric exercises5.

A computer model gave a different result15. Built from one woman, it found higher tendon strain in the heel drop than in the concentric heel rise15. Of the five exercises modelled, the bent-knee heel drop gave the highest average strain15. This model estimated strain, how much something stretches as a share of its resting length15.

The lowering phase did differ in other ways. In seven healthy people, quick ups and downs in tendon force showed up in everyone during eccentric exercises, but rarely during concentric ones5. In 16 healthy people, lowering showed more ground reaction force content at 8 to 12 cycles a second3. Ground reaction force is the push of the ground back up on the body. Lower-leg muscle activity was also lower in lowering than in raising3.

The calf muscles and knee angle

The gastrocnemius runs from the thigh bone to the heel bone, so it crosses both the knee and the ankle16,17.

Two studies came to different answers about what bending the knee does2,6:

StudyWhat it measuredWhat it found
18 people with Achilles tendinopathy, 18 withoutMuscle activity from skin sensors (EMG)Gastrocnemius more active with the knee straight; soleus unchanged6
19 healthy adultsActivity estimated by a modelSoleus and gastrocnemius activity at peak tendon force did not differ between knee angles2

Electromyography measures a muscle’s activity by picking up its electrical signals, often with sensors on the skin. In the modelling study, the gastrocnemius heads were shorter at peak tendon force with the knee bent2. The soleus’s shortest length was longer with the knee bent2.

A related test in 48 healthy people used isometric holds, where the muscle works but the joint does not move18. They pushed the foot down as hard as they could with the knee at three angles18. None of the three angles singled out the soleus or either gastrocnemius head18.

How the body adapts

What one session does to the tendon

Two studies looked at the Achilles tendon straight after a session of eccentric calf exercise7,19. In 14 people, the free tendon’s length and strain rose right after three sets of 15 heel drops7. The authors said this fits with mechanical creep, the slow stretch of a material under load7. The gastrocnemius aponeurosis, a broad, flat sheet of tendon, and its tendon did not change7.

The second took 11 men with mid-portion Achilles tendinopathy on one side, and nine without19. Mid-portion means more than 2 cm above where the tendon attaches to the heel bone9. Every Achilles tendon was thinner straight after the session19. Twenty-four hours later, each was back to its thickness before exercise19.

The painful tendons responded differently, though19. Their front-to-back strain response to the exercise was smaller than that of the other side or of the men without tendinopathy19.

What longer training does to tendon in general

The research below looked at tendon loading in general, not the heel drop alone20. A meta-analysis pooled exercise studies of at least eight weeks in healthy adults aged 18 to 5020. It found that loading made tendons stiffer and raised Young’s modulus, the stiffness of the material itself20. Cross-sectional area, a measure of thickness, grew by a smaller amount20.

Gains in stiffness depended on how heavy the load was, not on the type of muscle contraction20. Most programmes ran for 8 to 14 weeks20. Those of 12 weeks or more showed larger effects, though the difference was not statistically significant20.

Early studies in people with Achilles tendon pain

A 1998 study followed 15 recreational athletes with long-standing Achilles tendinosis, which is tendon wear seen in the tissue or on a scan21. They did 12 weeks of heavy-load eccentric calf training21. Afterwards all 15 were back to full running, with less pain21. Calf strength on the painful side no longer differed from the other side21.

Other studies looked at people with mid-portion tendon pain after 12 weeks of an eccentric programme8,22,23. One was a prospective study, which follows people forward in time22:

Who was studiedWhat was found
44 people in a randomised trial against a concentric programme82% of the eccentric group were satisfied and back at their earlier activity, against 36% of the concentric group8
78 people, 101 tendons, in a prospective study89% of tendons had a satisfactory result, with the person back at their activity level before the injury22
34 sedentary people15 of them, or 44%, did not improve23

How it compared with other exercise

A randomised trial of 58 people with long-standing mid-portion tendinopathy compared the eccentric programme with heavy slow resistance, a slow, heavy strength exercise10. After 12 weeks, symptoms had improved in both groups, and the gains held at 52 weeks10. Tendon thickness and neovascularisation, the growth of new blood vessels, also fell, with no difference between the groups10. On average, the eccentric group attended 78% of sessions, and the heavy slow resistance group 92%10.

Satisfaction in that trial was 80% in the eccentric group and 100% in the other group at 12 weeks10. At 52 weeks it was 76% and 96%10. Neither gap was statistically significant10.

Another randomised trial compared heel lifts, raised inserts in the shoe, with eccentric exercise in 100 adults with mid-portion tendinopathy24. After 12 weeks, the VISA-A score, an Achilles symptom questionnaire, rose by 26.0 points with heel lifts and 17.4 with exercise24. The difference favoured heel lifts and was statistically significant24. It came just short of the smallest difference the authors had set in advance as important24.

What reviews of the evidence found

Reviews pooling many studies reached mixed conclusions25,26,27:

  • A meta-analysis, which pools the results of several earlier studies, took in seven randomised trials in mid-portion tendinopathy25. Heavy eccentric calf training may do better than natural history, the condition left to run its course, but worse than other exercise programmes25. The authors had low confidence in these estimates25.
  • A review that screened 403 studies found limited evidence that eccentric loading gives better Achilles results than other loading programmes26. It found little evidence for singling out the eccentric part26. It also noted that up to 45% of patients with Achilles or patellar tendinopathy may not respond to eccentric training alone in some cases26.
  • A systematic review searches for all the research on a question in a set, checkable way. One looked at eccentric programmes for long-standing mid-portion Achilles tendinopathy11. Other programmes got similar results to the original one, though many of those studies had flaws or described their training poorly11. The best training settings could not be settled11.
  • A large review across many kinds of tendinopathy found that combining concentric and eccentric strength work may help more than eccentric work alone27. Most of its evidence was of low or very low quality27.
  • A network meta-analysis compares many options at once, including ones never tested against each other directly. One, covering 29 randomised trials in Achilles tendinopathy, suggested no clinically relevant difference between active approaches at 3 or 12 months28.

Years later

Two groups were checked years after the 12-week programme29,30. In 46 people five years on, the average VISA-A score had risen from 49.2 to 83.629. Of them, 39.7% were fully free of pain, and 48.3% had tried one or more other approaches29. In 25 people seen about 3.8 years later, the tendon was thinner than before30. On ultrasound, a scan made with sound waves, 19 of 26 tendons looked normal30.

Pain where the tendon meets the heel

Insertional pain lies within 2 cm of where the tendon attaches to the heel bone9. In 30 people with long-standing insertional pain, 10 of 31 tendons, or 32%, had a satisfactory result after 12 weeks22. A small pilot study in 27 people tried a changed version that did not lower the ankle into dorsiflexion31. At about four months, 67% were satisfied and back at their earlier activity31.

Progressive overload

A 2026 position stand describes progressive overload as the need to raise the stimulus on the muscle through a training programme32.

Adding weight

A randomised trial took 40 recreational athletes with mid-portion Achilles tendinopathy33. One group did heel drops on a stair edge twice a day for 12 weeks33. Each session was 3 sets of 15 with the knee straight and 3 sets of 15 with it bent33. Once the drops could be done without pain, weight went into a backpack in 5 kg steps33. The authors did not exactly track how much weight each person added33.

Fewer repetitions

Another randomised trial took 28 non-athletic people with mid-portion Achilles tendinopathy for 6 weeks34. One group did the recommended 180 heel drops a day, and the other did as many as they could tolerate34. The lower-volume group did not improve less in VISA-A or pain scores34. The groups differed at week 3, partly because the 180-a-day group got worse then34. At week 6 the difference was not significant34.

A systematic review found three trials using very similar programmes35. It concluded that how different doses compare was still unclear35.

Speed and depth

In a crossover trial, a study in which each person tries every option in turn, 34 healthy athletes did single-leg heel drops36. They carried an extra 20% of body weight36. Slow, 3-second drops to full dorsiflexion thinned the mid-portion tendon most straight afterwards36. Shallower slow drops and fast drops thinned it less36. Only the slow, full-depth drops raised a measure of tendon stiffness straight afterwards36.

Connections

The tendon it loads

The heel drop loads the Achilles tendon, which joins the calf muscles to the heel1,2. The tendon holds fibres from the soleus and from both heads of the gastrocnemius37.

The muscles it works

  • The gastrocnemius, both inner and outer heads, which cross the knee and the ankle6,16,17.
  • The soleus, a wide, flat calf muscle beneath the gastrocnemius1,6.

The calf raise also loads the Achilles tendon14.

Eccentric heel drop loads

Eccentric heel drop loads the same tendon as

Eccentric heel drop is progressed by

Sources

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Every source the library cites

Changes

  • Added a Progressive overload section.
  • Tidy pass: minor review findings fixed, glosses aligned with the reviewed glossary.
  • First published.