Rehabilitation of tendon problems: gradual loading and exercise

Tendon problems are often called tendonitis, but the term tendinopathy is used in professional language [1][2]. The author of an NHI article on heavy slow resistance training points out that the terms tendonitis and overload may not explain the problems correctly, because several factors can contribute [7].

Rehabilitation is therefore not only a period of offloading. It consists of exercise in which the load is increased over time, and in which the muscle attached to the tendon in question is trained [1][7].

The guideline for Achilles tendon pain recommends that you do not rest completely, but stay active within what the pain allows [1]. NHI describes that with offloading the symptoms often improve within days to weeks, but that rehabilitation then often takes several months [2].

For plantar fasciitis, NHI describes offloading in the acute phase and adapting activity so that running and prolonged walking on hard surfaces are limited. Cycling and swimming are mentioned as alternatives that maintain fitness without loading the foot [5].

The guideline for Achilles tendon pain recommends loading exercise at as high a load as the individual tolerates, at least three times a week. The type of loading is not restricted to eccentric exercise, and concentric, isometric and other forms can be used [1]. The programme is progressed according to pain tolerance and function. With a highly irritable tendon, heavy loading may be poorly tolerated early on, and pain during and after the exercises can be rated on a scale from 0 to 10 [1].

The programmes vary between the sources. Lægehåndbogen describes eccentric training and reduced activity for Achilles tendon pain, with gradually increased loading and exercise for up to three months [3]. NHI describes heavy slow resistance training three times a week over twelve weeks, in which the load is increased while the number of repetitions falls. The description is based on a Danish study of jumper's knee from 2009, in which the differences between the training forms were small after twelve weeks and clearer after six months [7].

An editorial in Tidsskriftet writes that exercise treatment most likely should be dosed differently in different patient groups [6]. The dose is therefore adapted to the individual.

For Achilles tendon pain, a temporary heel lift can be used as an addition to exercise [1][2]. Night splints and therapeutic ultrasound alone are not recommended [1].

For plantar fasciitis, the guideline gives manual therapy of joints and soft tissue, stretching and taping the highest grade of evidence, and strength training for the foot and ankle is recommended as part of the programme [4]. Taping applies to short-term improvement and is used together with other physiotherapy [4].

It varies. NHI writes that rehabilitation for Achilles tendon pain often takes several months [2]. According to Lægehåndbogen, active athletes tend to have recurrences and a chronic course [3]. An editorial in Tidsskriftet states that an episode of tendinopathy often lasts ten to twelve months, and urges clinicians to lower expectations of rapid improvement because injuries in tendon structures take time [6]. The editorial is from 2010, and the figures apply to tendinopathy in general.

In plantar fasciitis, most people improve within one year, and for some the condition becomes chronic [5].

If the symptoms do not improve after a period of adapted loading, or get worse, there is reason to have them reassessed. The guideline for Achilles tendon pain mentions that imaging may be relevant when the diagnosis is uncertain or improvement fails to appear [1].

If you get sudden pain in the Achilles tendon and cannot put proper weight on the foot, you should seek a doctor. It may indicate that the tendon has ruptured [8].

A physiotherapist can examine where the problems are and what triggers them, and together with you make a plan for loading and exercise that suits your situation. When the diagnosis is uncertain, diagnostic ultrasound may be relevant. You can also read about physiotherapy and running injuries.

Should I rest when a tendon hurts?

The guideline for Achilles tendon pain does not recommend complete rest. You should stay active within what the pain allows and train loading of the tendon [1].

How often should I train the tendon?

The guideline for Achilles tendon pain recommends loading exercise at least three times a week, as heavy as the individual tolerates [1]. Other sources describe other programmes, and the dose is adapted to the individual [3][6][7].

How long does rehabilitation of a tendon take?

It varies. For Achilles tendon pain, rehabilitation often takes several months [2]. An editorial in Tidsskriftet states that an episode of tendinopathy often lasts ten to twelve months [6].

Can tendon problems return?

Yes. According to Lægehåndbogen, active athletes tend to have recurrences and a chronic course in Achilles tendon pain [3].

The article on diagnostic ultrasound describes what the examination can show in tendon problems. You can find more articles in the overview of articles.

This article was written by Dr.Dropin Fysikalske and is based on the sources listed below. It gives general information and does not replace an examination by a healthcare professional.

The websites were accessed and read on 22 October 2026.

1. Chimenti RL, Neville C, Houck J, Cuddeford T, Carreira D, Martin RL. Achilles pain, stiffness, and muscle power deficits: midportion Achilles tendinopathy revision, 2024. J Orthop Sports Phys Ther. 2024;54(12). Link

2. Akillessenebetennelse (Achilles tendonitis). NHI.no. Last updated 15 October 2024. Link

3. Lind M. Akillestendinose. Lægehåndbogen, sundhed.dk. Revised 9 October 2026. Link

4. Koc TA Jr, et al. Heel pain, plantar fasciitis: revision 2023. J Orthop Sports Phys Ther. 2023. Link

5. Plantar fasciitt (hælsmerter) (plantar fasciitis, heel pain). NHI.no. Last updated 22 September 2025. Link

6. Behandling av tendinopati (Treatment of tendinopathy). Editorial, Tidsskriftet.no, December 2010 (author not stated on the website). Link

7. Dahl R. Heavy slow resistance training (HSR). NHI.no. Last updated 27 March 2019. Link

8. Lind M, Larsen EP. Akillesseneruptur (brist af akillessenen). Patienthåndbogen, sundhed.dk. Last updated 24 September 2025. Link