Achilles Tendonitis with Increased Frequency of Running
What is Achilles Tendonitis / Tendinosis
Achilles Tendonitis, or more correctly Tendinosis, is thought to be caused by overuse which causes microscopic areas of damage to the tendon.
These areas of microtrauma are quite common with exercise and normal daily activities, and the body copes by repairing these damaged areas on an ongoing basis.
However the cause of Achilles tendonitis with increased running is due to the fact that this repair process is not able to cope with the repeated strains below the injury threshold of the tendon, inducing microdamage or as I will call it from now on “damage”.
This “damage” accumulates and leads to mechanical breakdown of the Achilles tendon which develops areas of degeneration – Achilles Tendinosis.
Training Causes of Achilles Tendonitis
- an increased frequency of running over a short period of time
- a sudden increase in the length and/or speed of runs
- repeated running uphill as part of a training regime
- conversely repeated runs downhill!
- running on cambered surfaces
Damage / Repair Cycle of Running
As mentioned above there is a normal ‘damage / repair’ cycle that takes place in the tendon.
If you allow enough time after a training session then there is full recovery of the “damaged” area.
This is represented diagrammatically.
The blue dotted line represents injury.
The red line represents the “damage” done by a training session.
There is enough time for full recovery to take place.
Achilles Tendonitis with Increased Running or Training Sessions
If you suddenly increase the number of runs or training sessions that you do each week then the repair part of the cycle has less time to finish its role before you start your next session.
This leads to a cumulative effect of degenerative changes taking place in the tendon.
When this reaches the blue dotted line – you feel injured and there is breakdown of the structure of the Achilles Tendon.
In simple terms degeneration (tendon breakdown) is exceeding regeneration (tendon repair).
Avoid Achilles Tendonitis with Increased Running or Training
If you were to repeat the same runs or training routine at a frequency that allows full recovery then the tendon actually gets used to the level of stress applied to it.
This reduced “damage” with each successive run is represented in the graph.
Think of this as a training effect on the tendon.
However the idea behind regular training is to get fitter and achieve more so training at the same intensity is pointless.
The key to success is to progressively increase your training in such a way that you allow the “damage” to the Achilles recover sufficiently before increasing the loads on it.
That is where cross training and structuring your workouts is essential.
The 10% rule for runners weekly mileage comes to mind.
The 10 Percent Rule for Runners
The runners 10% rule states that you should not increase your weekly mileage by more than 10% week on week.
Personally I don’t necessarily agree with that but it’s not a bad place to start.
It’s too restrictive for beginner runners and perhaps too generous for elite runners.
If you are starting out and especially if your are starting back after an injury or lay-off then my advice would be to “listen to your body”.
By that I mean if your are sore after a session then take it easy for a few days – do some cross training instead of running.
Follow hard runs with easy runs or rest days.
Space out your workouts evenly through the week or month.
Build in an “easy” week (about 70-75%) every 4-5 weeks.
If you feel tired or sore then you are doing too much – REST!!
The Achilles can actually respond to regular loads over a period of time. Some studies have shown that there is an increase in cross-sectional area of the tendon (thicker / bigger) after ongoing regular exercise. Other studies have shown a difference in cross-sectional area between the dominant and non-dominant legs of the same individual – you use the dominant leg more. Yet more studies have shown no difference at all!
The more regularly you exercise the more the tendon is able to withstand the stresses applied to it
BUT and it’s a BIG BUT ….
you need to allow for the repair part of the cycle to take place effectively.
That’s why marathon runners like Paula Radcliffe can churn out apparently massive mileages each week and stay injury-free.
However when they do get injured it takes them a long time to get back to normal because World Record holder-or-not she has to follow these same basic rules on her rehab journey back to full race fitness.
This entry was posted on Tuesday, November 16th, 2010 at 9:10 am and is filed under Achilles Tendon / Calf, Achilles Tendon Injury - Achilles Tendonitis Injury, Pain and Repair. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.