Bulletproofing for Runners

Bulletproofing for Runners

As the weather becomes warmer and we start to come out of our winter hibernation, the number of runners hitting the pavement is going to substantially increase. A new outdoor running season may mean breaking in some new gear, setting sights on new PBs and, most importantly, making sure you stay healthy throughout the season. 
This article is for the novice, amateur and experienced runner, so sit back and dive in to learn how to keep yourselves strong and resilient throughout the running season!

Injury Mechanisms
According to the literature, the largest predictor of an injury is a rapid increase in loading over a short period of time.The literature also proposes that 60-80% of injuries are a result of training error, meaning that training load is responsible for causing injury. Interestingly, there is a lack of conclusive evidence in the literature linking running mechanics to injury. Many alterations in mechanics may actually be due to an injury itself, and it’s hard to conclude what came first; the injury or the change in mechanics. Classic chicken and the egg scenario.

Wait…am I saying that the way you train actually can influence your risk of injury? You would think this would be a very common thought, but it is often forgotten that training is a stress on the body that needs to be carefully monitored. Stress is needed to create change but we need an optimal amount to do so; not too little and not too much. We need to find the sweet spot and continue to discover where that sweet spot is as we get bigger, stronger and faster. We will take a closer look at using training variables to mitigate injury risk later on in this article

Load vs. Capacity
Tissue capacity is dependant on multiple factors, including tissue strengthmovement control (i.e., body awareness), mobility (active control of your range of motion) and history of previous injury. It is also influenced by some lesser known factors, including: 
  1. Non-musculoskeletal intrinsic risk profile
    • Diet, age, BMI, genetics, medications (corticosteroids, anticonvulsants), hormonal changes (around menopause), and metabolic issues
  2. Brain and central nervous system changes
    • Central sensitization and response to exercise
  3. Psychosocial factors (the perception of pain)
    • Stress, mood, fears, beliefs, motivation, and rehab behaviours
Training load can be broken down into 3 main subcategories that we can alter:
  1. Volume: How much (i.e., number of kilometres/miles in a given week)
  2. Frequency: How often (i.e., how many times a week you are running)
  3. Intensity: How hard (i.e., amount of effort of each run)
These are not the only training variables, but these are the ones that we can most easily record and modify to help avoid increasing the risk of injury throughout the running season.

Once a tissue has become injured, it inherently has a decreased ability to handle load, altering the capacity of the tissue. This means that there needs to be a gradual re-introduction of load to the tissue during the rehab process. 
Have you ever taken a week or two off of training due to an injury and then gone back at the same training load only to find that the nagging pain or discomfort came back relatively quickly? That’s because the tissue didn’t have a chance to adapt with an appropriate loading strategy. “Zero to one hundred real quick” is only okay as a lyric in a Drake song, not when it comes to rehab and training. 

Injury Prevention 
Injury prevention during a busy running season can be done by managing training load, while at the same time working to increase the tissue’s ability to manage load with strength training. The literature has recently proposed that one of the best ways to manage training load is to compare acute workload to chronic workload. 

Acute/chronic workload is a measurable indicator that compares the training load over the previous 4 weeks to the current week. By using rate of perceived exertion (RPE) of each run and multiplying it by the duration of each run, we are able to create an arbitrary unit that can be used to measure workload ratios. Rate of perceived exertion is a number out of 10 that is personally associated with the difficulty of that specific training bout.

Calculating training load for a single run would be as follows: 
8.0 RPE x 20 minutes = 160 arbitrary units (this is your training load)

Calculating the acute to chronic workload ratio would be as follows:
160 (average of the previous weeks training load) / 150 (average training load over previous 4 weeks)
= 1.07 (acute:chronic workload ratio)

An increased risk of injury is associated with an acute:chonic workload of greater than 1.25 (with a significant increase in risk of injury when the ratio is greater than 1.5). The proposed “sweet spot” for training is between 0.8 to 1.25.

Strength Training
Strength training has been shown to improve running economy and decrease the risk of injury. There is strong evidence that strength training is the only way to expose tissues to the stress that is necessary for positive adaptation - which in this case is an increased capacity of the tissues. A high intensity approach of using 70% of 1RM (1 rep max) is more effective than a low intensity approach, however there need to be a gradual increase to that amount of weight. The main focus of strength training for runners should be on lower body muscular strength and muscular endurance, upper body posterior chain muscular endurance, and core muscular endurance

Points to Remember:
•  Load > tissue capacity = tissue injury
•  Most common cause of injury in runners is due to training error (rapid increase in load over a short period of time)
•  Modifiable training factors are volume (how much), frequency (how often), and intensity (how hard)
•  Once a tissue is injured, it inherently has less ability to handle load
•  To avoid injury in runners, care should be taken to monitor load management and to participate in strength training
•  Use the acute:chronic workload ratio to avoid overtraining

If you have any questions about running training and how to make sure you are mitigating injury, come on in to Catalyst Health and one of our knowledgeable practitioners would be happy to help!

Written By: Dr. Dhanbir (Danny) Dulay, D.C., B.Sc. (Kin), CSCS
Medical Acupuncture Practitioner 
Functional Range Release Practitioner
Strength and Conditioning Specialist
Instagram: @dulaydc
Available for appointments at our Richmond location Monday - Friday


Note: only a member of this blog may post a comment.