Sometimes the blogs I write take quite a lot of research to do… hence, there can sometimes be quite a time between the blog posts! Longer than I would like, but I’m a human and not just buying canned material or writing vacuous posts!!! However, every now and again I see something that gets my attention and I feel the need to respond to it or comment about it rapidly. Sometimes, it is because it is a great article and provides information that I think you NEED to know. But, there are times I think you need to know because there is an issue with the research that might be overlooked when big headlines are produced in the media! Today’s blog is due to the later case.

Strength Training & Runners – My Bias Challenged!

For my clinical practice and in making decisions on other matters I do my best to follow objective scientific evidence. However, I know that I, like all of us, am biased in my beliefs. So, when I see an article titled “A Randomized Study of a Strength Training Program to Prevent Injuries in Runners of the New York City Marathon” my ears perk up! I encourage runners to strength train because I believe it reduces injuries, so I expected this study to fit with my biases!  Let’s quickly unpack a couple of things that interested me from the abstract (the summary) of the article:

• Authors and Journal – The article was in “Sports Health” which is the journal of the American Orthopedic Society For Sports Medicine (AOSSM). This is a well-known, high-quality journal.  It was also published by a group of doctors at the Hospital for Special Surgery in New York which is a top US institution.
• Hypothesis: “A 12-week strength training program would decrease the rate of overuse injuries resulting in marathon non-completion and improve race finishing time.” Yes, this definitely fits my bias, as this is what I see with the clients I work with!
• Method: Randomized Study – This is not just a small to moderate series of cases, where a biased clinician (like me!) has found a positive response between strength training and running. Instead they randomized a group of 720 people running the New York Marathon into a strength training group or an observation group. So it was a large study of runners where some were randomly selected to do the marathon following the addition of strength training for 12-weeks and some trained as they normally did. This randomization helps to reduce bias and helps to make sure that the intervention is done on a wide variety of subjects.

So, to this point of the abstract I am in hog heaven! This is the article for me!!! But, if I skip to the conclusion, my bubble could burst:

“this self-directed strength training program did not decrease overuse injury incidence resulting in marathon noncompletion” 

Is My Bias Wrong?

At first glance, it seems so. BUT: this example highlights the importance of reading the full abstract and then getting hold of the full study. In the method section there is a hint to an issue:

“The strength training group was instructed to perform a 10-minute program 3 times weekly using written and video instruction”

This is not any form of strength training that I would use with my runners! Would my runners like to use this sort of protocol and get results? Sure!!! If they could reduce injuries with only 30-min of strength training a week they would be elated! However, in the patients I see (and this is my bias) the strength training needs to be more significant. We may only need two sessions per week, but we need to use heavy loads and the sessions would likely take 30-min each. There is research pointing to this, but no large randomized trials.

Limitations in the Research

When we pull up the full article, there is reference to other scientific articles defining why they selected the exercises they did. So, they show there is benefit of the exercises they have used versus others. But, when we read the methodology section further and see the materials they gave to the athletes we see the big problem – they do not provide any parameters other than reps and a statement to Begin with the “Beginner” exercises and move to the “Advanced” after successfully completing the exercises without difficulty”. There are no other guides and no reference to well established recommendations by the likes of the American College of Sports Medicine (ACSM) of the National Academy of Sports Medicine (NASM). This presents two big issues – 1) Are they really strength training at all? I would argue they are not as they are only using body weight loads and this is insufficient to generate strength against what the body typically experiences with running (There is more about this in a previous blog). 2) The lack of specific instructions also means that they may have used different parameters – some might have used weights, some might have used harder intensity. Their instructions are not sufficient and will have led to a greater level of variety. Both of these issues mean their conclusion is right in that “this self-directed strength training program did not decrease overuse injury incidence resulting in marathon noncompletion” but it does not show that strength training programs do not reduce injury incidence.

In research, as part of the discussion, the authors move into a section of text we call “limitations”. These are the things that they see as issues in the study that could limit the applicability of the research. Researchers are humans, so they make mistakes in study design, they make assumptions that while the research takes place are proven not to be true and this is where they should discuss this. This is where I would expect them to consider what we have above, and they do make some lip service:

“Despite careful selection of exercises included in the strength training program based on available evidence, the program itself may not have been effective at producing the strength gains or neuromuscular control needed to maintain optimal running biomechanics during long runs. Improved strength would likely be achieved with a longer program or by recommending that it be performed more frequently, though this would decrease compliance”

However, I am going to argue that their literature search was not very thorough as the only parameter they seem to be able to see in adjusting the exercises is temporal (i.e. time). The athletes may get stronger if the program was run longer, the exercises were done more frequently. They make absolutely no mention of weights!!! It makes no mention of the various guidelines that have been produced for strength training from the human research conducted to date.

What Might Some of The Headlines Say?!

Now, the runners who did the strength training thought it was useful, so in the end the authors do not  conclude with recommendations against strength training. They leave it open that strength training could be beneficial, but I think as we have shown they may not understand strength training! I think that if this research is picked up by the media, it could lead to people not strength training as they think there are no meaningful benefits. Again and again, I see athletes who have found benefit from heavy load strength training to get them out of injury ruts or to have streaks without injury. Hopefully, more research will follow that will prove this, but in the meantime I would suggest doing two sessions per week of heavy strength training using exercises that hit the main muscles. I will return with a blog that expands on this topic. 🙂

My Bias: Strength Training is Good For Runners on Many Levels!

Some runners might worry that they will bulk up, but with the volume of aerobic  training you are doing this is unlikely. Some will ask if they should do light weights and high reps as they need to work type II muscle fibers and get the aerobic benefits, but I would agrue that their running is already providing those aerobic benefits. Instead, the heavy loads are helpful for bone health (blog here, especially important for females) and tendon health (blog). Some will worry about injuring themselves as they are unfamiliar with proper weight training technique – I can understand this, and would only suggest doing things on your own that you are comfortable with and even then keeping pain/soreness in a reasonable place. This also where assessment by a PT that works with runners can be important and why I offer the Bulletproof runner program. While I cannot  guarantee 100% injury prevention, but I have seen people have less injuries than they are used to when they start lifting heavy weights. If you have questions or critique, let me know!

Reference:

• Toresdahl BG, Mcelheny K, Metzl J, Ammerman B, Chang B, Kinderknecht J. A Randomized Study of a Strength Training Program to Prevent Injuries in Runners of the New York City Marathon. Sports Health. 2020;12(1):74-79.