Applying the Current Acute-to-Chronic Workload Ratio Considerations to Running Related Injury Prevention

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Chris James, SPT, Colton Johnson, SPT, Cailey Roth, SPT, Justine Schroeder, SPT

14 Comments on “Applying the Current Acute-to-Chronic Workload Ratio Considerations to Running Related Injury Prevention

  1. Great job!
    1. You mentioned ACWR only being one piece of the puzzle for preventing RRI. What other factors should coaches and therapists be looking for?
    2. How do you see foresee ACWR being used in the clinic?

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    • Thanks for the questions Jenna!
      Other factors that may contribute to the development of RRIs include nutrition, sleep, strength development, and stretching. Personal factors also contribute such as genetic factors and how an individual’s body responds to stress.
      ACWR can be used in the clinic when working with athletic trainers and coaches to assist in guiding injury prevention training strategies. It may also loosely be applied when working with athletes who have previously recovered from an RRI. Of course, there would be significant additional factors to consider such as the previous injury which affects re-injury risk, but it may be a good guiding factor and a great area for future research in determining how the current ACWR range is affected by previous RRIs.

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  2. Thorough and informative presentation!

    ACWR seems to be a time-consuming method not only for coaches, but for athletes as well. Has the duration and effort required to use this method been addressed in the articles you have included within your study? Additionally, in the Conclusion you mentioned there are various other factors that come into play when analyzing injury prevention. Is the information provided by ACWR alone and the time and effort it requires worth pursuing when there are so many other factors that also come into play?

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    • Thanks for the question Erin! None of the articles we included in our study went much into depth on the amount of time or effort it took specifically to calculate ACWR. But you are right, determining, following, and programming training regimens that fall within the desired ACWR for athletes requires one to be organized and meticulous in their training planning. So although it may be more work to follow this injury prevention strategy, it is up to each individual or coach to determine whether they consider it “worth it”. Our studies included did not discuss any efforts made to control other injury factors such as enough sleep or good nutrition, but likely if those factors are not being monitored or promoted, implementing those would be a more simple and time-effective way to implement injury prevention rather than using ACWR as a first strategy to reduce injury risk. Alternatively, in settings where athletes are participating in healthy habits, getting good sleep, eating good nutrition, and are warming up and cooling down with training but are still experiencing injuries, using ACWR may be a good option to pursue.

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  3. Awesome job on the poster, it looks great! In your clinical relevance portion, you mention that if clinicians, coaches or runners are to implement the ACWR in their training they should do so cautiously, so I am wondering if through your research did you find a certain population that this ACWR works better for (ex. males vs females or age) that has more success or fewer negative effects with this method?

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    • Good question Cassidy, thank you! So to answer your question, we did not find any research to say that any one population would benefit from ACWR more than another when it comes to gender or age. I think the reason we used the term “cautiously” in that context was more to emphasize that our primary conclusions and recommendations were theorized based off of research that was not exactly specific to runners only. Due to limited available research on the topic, the research that has been completed on ACWR looks at various other sports that involve different physical demands than running alone. There may be variables that our research could not have accounted for when it comes to the running athlete specifically, and running injury prevention. Therefore, coaches and clinicians need to proceed with caution whenever they increase an athlete’s overall workload to ensure that their athletes remain injury free even with the use of ACWR.

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  4. Great job on the poster guys!

    After reading your poster and referencing your sources, it appeared that the majority of your sources pertained to soccer and American football players (7 sources), while 4 sources studied runners.

    Soccer and American football are more of an open and unpredictable environment with many outside factors (i.e., cutting, dodging, shorter intervals/bursts of speed and power) in comparison to the more closed and predictable environments of track and cross country runners (i.e., golf courses, trails, and track surfaces). With that being said, how was ACWR utilized differently between the two types of sports? Or was there any difference at all?

    Additionally, in your conclusion it was stated that ACWR has some evidence to benefit runners, was there any evidence supporting its use with soccer and football players?

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    • Hi Kiana, great questions! As for the sources, only two of the studies actually assessed ACWR in runners (Dijkhuis et al, Johnston et al), the other two resources I believe you are referring to were for the purpose of background material and reinforcing a standardized definition of what constitutes a running-related injury (Yamato). You are correct in that soccer, American football, and rugby are all very unpredictable and have different biomechanical requirements than those of runners. It may help to think that ACWR is an encompassing term for a method to determine both internal and external workloads on an athlete and its relation to injury. Within our review, we found that there was no standardized method of determining ACWR, different studies used different measurement techniques and different timeframes ultimately harming the external validity because we can’t directly apply the results to a framework for runners. Within the two consensus statements we referenced, both suggested using a form of sLoad, which takes into account the total load for each training session, or training week, relative to the sport it plays. This method would be good framework to use as it can be applied across varying sports. Per your last question: the majority of the evidence surrounding ACWR comes from its use in soccer and rugby/Australian football, so yes there is a fairly large body of evidence supporting its use. For American football, we found a few studies using ACWR, but we were only able to include one as the others included traumatic injury, so there is some evidence for American football. Great questions!

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  5. This is an interesting and well-put together poster!
    I noticed that one of the studies was only 28 days long, how you think that could have affected the results that they got?
    Additionally, from the research you guys have done, if ACWR were to be implemented, what settings/ populations do you believe it would be most appropriately utilized? For example, could this be useful for high school runners/ athletes as well as for more professional runners/ athletes?

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    • Hi Megan, thanks for your questions! The ACWR is calculated by taking the sum of 1 week over the average weekly workload of the last 4 weeks. In the article you’re referring to, researchers calculated their athlete’s ACWR and compared it to any injuries sustained. This study gives an accurate representation of the athlete’s workload without manipulation. The researchers did not chase the athlete’s “sweet spot” “but compared calculated ACWR to sustain injuries. Potential follow-up research for this study could have been to continue following this cohort and manipulate the workload until a workload of 0.8 – 1.3 or the “sweet-spot” for each athlete was reached and then evaluate the number of injuries that occurred compared to the initial ACWR.

      Based on the research we collected, I believed an ACWR would be best utilized in populations where athletes are practicing or working at their sport almost year-round. For example, your college or professional athletes. The athlete’s seasons would give you adequate time to calculate ACWR and slowly manipulate the workload until you find the individual “sweet- spot” for each athlete without exposing them to too much risk.

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  6. Great research poster everyone!
    Since ACWR can be used for chronic/overuse related injuries, especially RRI’s, could it be applied to upper extremity sports such as volleyball, softball, and baseball?

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    • Thanks, Matti, for the question! Yes, just like running, an ACWR can be applied to different sports to assess overuse injuries. ACWR has been studied for its effectiveness at monitoring and predicting injury risk in all levels of competition for various sports such as cricket, tennis, baseball, cross-fit, rugby, and other impact sports. The most significant difference when looking at sports such as volleyball, softball, or baseball would be considering overuse injuries of the shoulder, elbow, and hand. When conducting this type of research, it is also essential to take out any injury due to a traumatic incident.

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  7. Great job on the poster. I was wondering if ACWR could be applied to multiple sport athletes? They may not be performing the same sport year round, but if they are continuously involved in a sport would ACWR still be a beneficial predictor of RRI’s?

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    • Hi Ali,

      Great question! As with our conclusion on applying it to running, you could cautiously apply ACWR to multi-sport athletes. From a literature standpoint, this wasn’t covered so applying ACWR in a population that has no evidence needs to be done cautiously and with good clinical judgement. Especially when you consider season timeframes for multi-sport athletes, the different training loads and shorter seasons would be disadvantageous to establishing consistent chronic workloads. Another thing to consider with multi-sport athletes is how quick their training progression occurs. With athletes that focus on one sport, they are training year round and have set macro and microcycles for their training, but with multi-sport athletes, those cycles become shorter while the demands on performance remain the same. Utilizing the International Olympic Committee’s and our recommendations of using session load (sLoad) would definitely be the best route as sLoad takes into account individual loads and perceived loads, so its more flexible in how its applied with ACWR. Hope that answers your question, thanks!.

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