Inoculating Runners: The Great Power of Evidence and Positive Messaging

In many of our previous posts we have discussed how positive messaging, pain science and encouragement are powerful aspects of physiotherapy treatment. We often discussed that we as healthcare providers must be aware of the verbal and non-verbal messages we send our patients such that we do not contribute to someone’s disability, and that the ultimate goal of treatment is to instill self-efficacy for patients to care for themselves. In this blog I hope to give you a “boots on the ground” view of how we might provide these messages to runners.


THE CONTEXT: I hope that we can all agree that we are in a health field, and as such we should be doing our absolute best to improve our patients health. This doesn’t just mean musculoskeletal health, it also means cardiovascular, neurological, and psychological/emotional health. Running provides an excellent option for the larger population to achieve these health benefits based on accessibility alone. Studies have shown that physical activity (including running) has a dose response to health benefits to a certain point. A study by Kyu (2016; Ref) demonstrated that an increase of weekly work from 600 METS (i.e. approximately recommended 150 minutes of moderate to vigorous physical activity (PA)) marginally decreased the risk of diabetes, ischemic stroke, ischemic heart disease, breast cancer, and colon cancer; but increasing to 3000 METS weekly decreased the risk by approximately 20% for these conditions. They also found that above 5000 METS weekly, there was no further risk reduction. This is a great example of the importance of PA. Additionally, cardiovascular exercise has been shown to increase circulating levels of brain derived neurotrophic factors (BDNF or “miracle grow for the brain”) at rest after 3 months of regular training (Ref). BDNF has been highly linked to the development, physiology and pathology of the brain. With a central role in modulating synaptic plasticity, it theoretically may influence such conditions as epilepsy and chronic pain (Ref). Finally, exercise has been shown to have a positive influence on depression. In a systematic review and meta-analysis by Lawlor (2001; Ref), they found that the effect of exercise was similar in magnitude to cognitive therapy. These authors also found that there was no difference between exercise type for this positive effect.

This is all to say that, based on the health research, if someone wants to keep running, then we should be doing our absolute best to keep them, or get them back to, running! Let us also remember that health was defined as, “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” by the World Health Organization in 1948 (Ref). As such, exercise and PA helps us be our best selves and is our “vaccine against disease!”

THE MESSAGE: “My (enter your favourite healthcare provider) says I can’t run anymore!?! It is bad for my joints!?!” I have run into many of these statements over the years from patients, and I would contend that based on the evidence above, as well as what we currently know about running’s effects on joints (see below), this is the wrong message to send! Instead we should listen to their goals, and enable these goals as best we can. To do this let’s ask what the evidence is on running’s effects on our joints.


THE EVIDENCE: A recent systematic review and meta-analysis by Alentorn-Geli (et al., 2017; Ref) examined the association between running level with knee and hip OA. The authors noted the need for this study based on the large discrepancy within the literature where some studies showing a negative effect of running and some showing no effect. They also noted that there had not been an adequate analysis on the effects of the volume of running on hip and knee OA. These authors included 25 studies in their systematic review, with 17 of these studies used for meta-analysis totalling 114,829 subjects. They broke down subjects’ running levels into sedentary/non-runners, recreational runners, and competitive runners, but also noted their inability to specifically define weekly mileages for recreational and competitive runners. These authors found that recreational running actually had a protective effect on hip and knee OA! The prevalence of hip/knee OA in recreational runners was 3.5% (95% CI: 3.38-3.63%) compared to 10.23% for sedentary/non-runners (95% CI: 9.89-10.58%) and 13.3% in competitive runners (95% CI: 11.62-15.20%). This an amazing finding that flies in the face of how we have viewed running as “wearing down our joints with use”. It turns out that the body will respond positively to the right amount of stress and load! Based on what we know about progressive overload with training and the positive response of muscular and cardiovascular systems at any age, I don’t think this should surprise us.


As Alentorn-Geli and colleagues were not able to determine what mileages defined recreational or competitive, we are left with a small problem of, “what do I suggest for my patients?” These authors pointed to 2 studies which might give us perspective for our recommendations. The first study by Konradsen (et al., 1990; Ref)  found that 21-42 km/weekly trail runningwas not associated with increased risk of hip/knee OA. The second study by Marti (et al., 1989; Ref) suggested that elite runners with a mean of 91 km/weekly running was associated with an increased incidence of hip/knee OA. This gives us a large variance to be able to prescribe: none is not helpful; some is really good; but a lot may not be advantageous. My bias is that “variety is the spice of life” and that keeping your movements and exercise varied is important when you are training at high volumes.

A separate prospective study by Chakravatry (et al., 2008; Ref) followed 45 runners and 53 control subjects over 50 years of age for an 18-year period to track changes in prevalence and severity of knee OA based on radiographic evaluation. By the end of the study they found no significant difference between runners and controls in prevalence (20 vs 32%, p =0.25) or cases of severe (2.2% vs 9.4%, p=0.21) knee OA, with the same number of subjects in each group having total knee replacements (3 subjects). Message: “running is not bad for you, even into your later years!”

I would also take a moment here to point out that the presence of knee and hip OA is not synonymous with pain and dysfunction (Ref, Ref). Moreover, I will point out there are associations between OA knee/hip pain and psychosocial factors such as depression and anxiety (Ref, Ref, Ref). To further emphasize my point, I will draw your attention to the fact that many individuals with depression and anxiety self-manage their symptoms with physical activity like running (in a Canadian study 23.5% of those with mood and/or anxiety disorders exercised 4 or more times a week to help self management; Ref)! Now let’s consider that message again: “My [insert your favorite healthcare provider] says I can’t run anymore!?! It is BAD for my joints!?!” How is this helping people?

1)      It is not absolutely true – some running is good for your joints!

2)      Let’s not rob our patients of their activity – it is keeping them healthy (knee and hip pain isn’t going to kill you, but inactivity is likely to!)

3)      Running may be positively affecting their lives in more ways that you might consider – don’t just think about the tissues of their hip or knee, remember the whole person!


Even when someone comes into our clinic with a symptomatic presentation of knee or hip OA, “motion is lotion.” Sure we might have to decrease the load for the short term (the “calm things down” phase), but we need to keep them moving! A bike is an excellent option here (Ref). Our job is not simply when we calm down their symptoms. We must help them get back to (or improve on) their level of exercise – the “build it up” phase (thanks, Greg Lehman). This is particularly important when we remember the research on increased activities positive effect on disease risk (Kyu et al., 2016; Ref). Here is where progressive strength training comes into play. A great study to get buy-in from runners on strength training is one by Storen (et al., 2008; Ref) that showed an improvement in running economy (less oxygen required) after 8 weeks of strength training (3 times weekly, 4 sets of 4 repetition max half squats added to their typical endurance training). These subjects were all highly trained runners, but the results suggest that in rehab, strength training can be helpful, especially while building up loads before or during their return to running.

THE HOW: This is a huge area! You can study and take courses endlessly to achieve the goal of returning your patient to running. So I will point you to some great resources, and then keep the advice simple.

High Quality Resources: Physio Edge podcast with Tom Goom, Greg Lehman, and Dr. Christian Barton; Greg Lehman’s running course; Tom Goom’s & Greg Lehman’s running blogs.


Educate: Build a positive expectation that the goal of running again is achievable (it will be rare that it isn’t). The evidence discussed above should help this process. Discuss an appropriate timeline to manage this positive expectation. It usually is going to take some work and time if pain is limiting your patient’s ability to run, but you may be able to modify some factors to keep them running.

Modify load: Often you will be able to keep someone running just by modifying things like distance or speed. The goal is to keep them active with out their pain sticking around after their run, or being significantly worse within a 24-hour period outside of the run. If you can’t achieve this, then a short period away from running might be helpful. This is when the loading mainly comes in the form of rehabilitation exercises.

Modify Technique: Pain science suggests that pain has to do with sensitivity and protection. As such, it may be possible that changing someone’s running technique in the short term, or even over short bouts within a run, may improve their pain response. Some things to try include – cadence; strike point (forefoot, midfoot, hind foot); forward trunk lean (15 degrees can change loads at the knee; Ref). Test it in the clinic on a treadmill! If you can change their pain with one or another of these cues, they may be able to keep running. The goal is to maintain some of the rehabilitation loading through running, and supplement with rehabilitation exercises as needed.


Physiotherapists are in a unique position in health care. By staying informed on the latest evidence, we can inoculate our patients against negative messages about the fragility of the human body. I believe it is our duty to our patients to help them achieve their activity and movement goals, but our duty to society and the healthcare system is to improve our patient’s health! This is where our primary knowledge that exercise is medicine can change our patients lives.

Educate. Empower. Encourage…& keep running!