Lessons from the Front: Running Injuries

If you're a runner or endurance athlete, you are familiar with the advice to slowly increase your distance each week. This principle is key to improving your performance safely. However, pushing too hard, too fast can have serious consequences, as I, physiotherapist Dana Tostenson recently experienced.

As physiotherapists, we are not above experiencing injuries ourselves. Despite our expertise in physiology, rehabilitation medicine, and having seen thousands of patients, we too are human, and as such can make mistakes and have accidents.

In this blog, I thought I would share my most recent injury and reflections on I will be not only rehabbing it but preventing it from reoccurring.

A common story

For context, while I am not a regular runner, I have been aspiring to complete a marathon. As such, starting in November I began running more frequently following a 30 week marathon program in preparation for the BMO marathon on May 4, 2025.

Training was going well. So well in fact, I decided I wanted to accelerate my progress, and jump  into a more challenging program (Note, that as a physiotherapist myself, I have heard this injury origins story more times than I can count).  

The result? After a week overloading, overrunning, and under resting I felt sharp pain just above my heel accompanied by significant swelling. There was no specific moment of injury, no pop, or snap. Simply the day after a good run, my body had decided it was time to take a rest.

Dana’s running data over the winter

Looking at the data, you can see in December there was a nice steady increase in running by approximately 2km a week, translating to an increase of 5 in my weekly load.

Researchers have found that runners were able to sustainably challenge their Achilles tendon between 4.5 and 6.5% above their typical weekly strain[1]. For simplicity’s sake, we can consider strain to be an increase in duration, speed, or elevation in a run.

The train clearly came off the track in the second week of January. This marks the point where I switched my program to a more aggressive track. Roughly speaking, it appears that I had increased my distance by almost 50% from the previous week. Clearly, this jump in load was far too much for my Achilles.

While there was no exact moment of injury, the accumulating bouts of overuse overwhelmed my tendon’s tolerance for use and my body’s capacity for recovery. This mechanism explains many of the “repetitive strain injuries” we see come into the clinic.

This type of injury is common among runners who increase their training load too aggressively. While cardiovascular and muscular fitness can improve quickly, tendon adaptation is much slower. Without adequate time for recovery, they the quality of healing occurring at the cellular level degrades and a cascade of inflammatory process occurs, leading to a painful and stubborn (if not rehabbed well) injury.

Achilles tendinopathy is common among runners who increase their training load too aggressively.

Treatment

The 5% Rule: A Smarter Way to Progress

There is no treatment better than prevention. To avoid injuries like Achilles tendinopathy, it’s crucial to follow a more measured approach to increasing training load. A good rule of thumb is to increase your total training volume by no more than 5% per week. This small, steady progression allows your muscles, tendons, and joints to adapt appropriately, reducing the risk of overuse injuries. While the change in activity feels minute, the compounding benefits are worth it.

Strength Training as Injury Prevention

In addition to gradual progression, supplementing your running program with targeted strengthening exercises can significantly reduce injury risk. Strengthening the Achilles tendon, calves, and surrounding muscles helps improve their resilience and ability to handle increased loads. Incorporating exercises such as single leg calf raises, heavy weighted eccentric heel drops, and plyometrics into your routine can provide the necessary support to your tendons. From our experience and research, incorporating strengthening routine targeting the legs three times a week will not only reduce your risk for injury but improve your run time.

Listen to Your Body

Feeling strong during a workout doesn’t necessarily mean your body is ready for a big jump in intensity. Pay attention to warning signs like stiffness, mild pain, or fatigue, and adjust your training accordingly. If you do develop symptoms of an overuse injury, addressing it early is key to a quicker recovery.

Respond but don’t overreact

As you can see in my running data, I didn’t completely stop activity after my injury. Rather, I significantly cut back my running in terms of distance and speed. I started with intervals of short jogs and long walks and progressively worked my way back to continuous runs. I often tell my patients experiencing tendonopathies or tendonitis to be OK with a little pain, up to three or four out of ten pain. More importantly, the key time to reflect on adjusting your programming will be the day after a bout of exercise. Just as in my case, I didn’t notice the pain until the next day. This is a pretty common characteristic of tendonpathies that we can use to inform future training. If you are more sore the next day, stick to or decrease the load in the next training bout. If you are not more sore in the tendon, consider another bout at the same level before considering increasing the intensity.

Need Help? We’re Here for You!

If you’re dealing with a repetitive strain injury or aren’t sure how to progress your training safely, come see us at Pursuit Physiotherapy. These injuries can be frustrating and slow to heal, but with the right programming and treatment, you can get back to pain-free running.

References

[1] Tsai MS, Domroes T, Pentidis N, et al. Effect of the temporal coordination and volume of cyclic mechanical loading on human Achilles tendon adaptation in men [published correction appears in Sci Rep. 2024 May 6;14(1):10343. doi: 10.1038/s41598-024-61081-8]. Sci Rep. 2024;14(1):6875. Published 2024 Mar 22. doi:10.1038/s41598-024-56840-6