Tendonitis and how to reload tendons safely

8 September 2021

In the last article, we covered what achilles tendinopathy is, why it occurs and how you can treat it. In this article, we take a wider view on tendonitis/tendon injuries in general and cover the relation between tendon loading and pain. We will also be guiding you on how you can reload safely. If you are having recurrent pains that never seem to go away with rest, you might actually be resting wrongly! This article will help you understand why a little bit better, read on to find out more!

Tendonitis and load capacity

Load capacity refers to your ability to perform without causing tissue injury. Both functional performance in sports and movements in daily activities require an adequate amount of capacity from your muscles and tendons in order to work optimally and be injury free.

There are 2 main reasons why tendons will overload:

1. Sudden increase in training volume 

This happens when you do activities at an intensity that your tendons are not used to performing at. Examples of sudden increase in training volume are as follows:

“I just ran 5km with my friend yesterday; nothing happened during the run, but i woke up with a lot of pain in my knee” In this case, this client has not been exercising consistently and last ran 6 months ago. 

“I followed Les MILLS on demand for a 6 week cardio program to lose some weight” While trying to follow the workout programme, this client did 50 jumping jacks, split jumps and burpees in the first workout. 

The affected tendon in both situations is not used to having to take load consistently for that intensity (5km or 50 jumping jacks) and that becomes a shock to the tendon to suddenly have to take on that load. Not having the adequate load capacity then puts you at risk of tendonitis. 

2. Accumulated fatigue 

Accumulated fatigue or overworked muscles resulting in tendonitis is very common when workout training programs do not include sufficient rest days. When planning a training regime, most people neglect planning for rest days to let the muscles recover.

“I have been on a 12 week program to train for nationals. I ignored my achilles when it mildly started to ache a week ago. It is now painful when i walk” 

Tendonitis can occur despite being an athlete used to the intensity of training. This client’s training program consists of twice-daily running sessions with 4 gym sessions on alternate days. This client has also just recovered from an ankle sprain 6 months ago. 

Most injuries occur when you exceed the capacity of the weakest link in your chain. Unlike a traumatic episode with a muscle or ligament tear, a tendon injury may not present with a clear mechanism of injury. 

The 3 stages of Tendonitis

Stage 1: Reactive phase: 

Common presentation of symptoms during this phase include acute pain with a significant loss in function. “My tendon looks very thick and swollen. It hurts to touch and it is painful to walk”. Early load management in this phase is crucial; as a reactive tendon has the potential to get better or worse.

Stage 2: Reactive on degenerative/ dysrepair: 

“I have been having this grumbly pain for a while. It got better, but now i feel like i am back to square one” 

Unlike a reactive phase, this will not be the first time you experience these symptoms. This often happens when we go too much too soon, also known as the Boom Bust Cycle.

Unlike other tissues, it is very tricky to determine tendon capacity – factors like muscle bulk, strength and pain cannot be used as a measure of tendon capacity. As a result, tendon injuries are more susceptible to entering the Boom (quick build up once pain settles) Bust (set back) cycle. Here are some tips for you to avoid entering the cycle! 

  1. Pacing- Injury reduces your capacity. Make sure you build up slowly and cater time for your rest days. 
  2. Delayed Pain – You may feel great after your warm up, but too much load now and you will feel it tomorrow. 
  3. Set up a training routine with goals. If you are not sure how to do it, we can help you out! 

Stage 3: Degenerative tendon: 

This is the final stage of the spectrum. It is suggested to be irreversible with poor prognosis. However, not to worry! As mentioned in the next section, your tendon will have regions undergoing different stages of the spectrum. 

Common symptoms include constant moderate pain, daily morning stiffness with palpable bumps along your tendon. 

Managing function with tendinopathy

It is important to view your tendon health as a spectrum, meaning that there is continuity between these stages and that you are not confined to one certain stage. It is also possible to have multiple spectrums at the same time in the same tendon. 

Imagine this as your tendon:


A single tendon consists of hundreds of fibrils. With an acute flare-up, the tendon would potentially have 30% being reactive on degenerative, 40% in normal function, 15% in dysrepair and 5% in the degenerative spectrum. You are targeting the 30% that is reactive on degenerative to reverse it back to normal function. 

How to prevent tendons from degenerating? 

After finding out that some of your tendons are in bad shape, you may be wondering – how can I make my healthy tendons healthier or prevent them from degenerating? There are 3 main factors that you need to consider, namely the frequency, volume and intensity of your rehabilitation to achieve the goals of your management. 

The relation between load capacity and tendonitis

If you are not loading, you are unloading. If you are not increasing capacity, you are increasing weakness. 


Imagine your tissue capacity as a 500ml cup – after an injury, your cup becomes smaller (400ml). So if you try to put the same amount of load (500ml) into it, it will overflow. SImilarly, after an injury, your tissues are not able to handle activity at the same frequency, volume or intensity as before and if you try to get back to where you were, your tissue will not be able to hold up.

Depending on the load input, a reactive tendon can move either up (more pain) or down (less pain) in the spectrum. As shown in the diagram above, 

Tendon loading will include isometric and functional strength work, eventually progressing to plyometrics to allow the tendon to adapt to the end desired goal  Furthermore if the desired goal is to get to an even higher level of performance, complex loading will be required to address any deficits present in the kinetic chain. 

If you are think you may have tendonitis or if you are experiencing pain, get in touch with our team of physiotherapists. Core Concepts physiotherapists are experienced in treating sports injuries and helping our clients get back to their full function. Contact us to book an appointment