Estimated reading time: 10 minutes
Shin splints, hamstring strain, knee pain, I bet at least one of these is familiar. If you haven’t personally suffered from one of these injuries, chances are good you know someone who has. Over 8.6 million people are injured in sports and recreation every year in the US alone, according to CDC estimates. These injuries are most frequently caused by general exercise. Half of all sports injuries warrant the attention and expertise of a doctor or other health professional in a non-emergency setting.
Having experienced a terrible stress fracture myself, I know the mere thought of being unable to continue something that a lot of your friendships, identity, and passion revolve around due to injury is unfathomable. Not to mention, injuries stick around for a while as healing can last for weeks, months, and even years. Despite people’s deep aversion to the thought of getting injured, it happens time and time again, even to the most seasoned of athletes.
Although athletic injuries may seem inevitable, they are not! Just managing how much you work out and how quickly you increase or decrease your training volume can make a huge difference. In some cases, proper workload management can reduce your risk of athletic injury by up to 60% even 80%. Understanding how much training your body can handle will ensure you do not overtrain or undertrain, which can lead to soreness, pain, and injury. This will allow you to customize a training plan that keeps you healthy and progresses you towards your goals. In some cases, proper workload management can reduce your risk of athletic injury by up to 60% even 80%. Click To Tweet
Workload’s Role in Your Training
Tracking and analyzing workload helps you to optimize your training by showing you your response to different types of training. Simply put, “workload” is a measure of work done in training. Workload quantifies your workout based on its intensity and volume, whether that’s distance, duration, or another unit of measurement. Considering this factor in your training will help you to improve your fitness level, limit soreness, and prevent injury.
Workload is both how much you do and how hard it feels
External load is the intensity and duration of exercise. It represents the force put on, and produced by the body. This includes metrics like:
Internal load is your individual response to their training. This is a little bit more difficult to monitor but can be extremely meaningful using even very simple tools :
- Perceived Exertion or RPE (how hard that workout felt on a scale of 1-10)
- Heart rate
- Blood markers
- Saliva markers
Here’s a workout example to distinguish between external load and internal load: Paul runs for 13 miles at 8 minute pace. He finds the workout to be moderately difficult (6 RPE), meaning he definitely could have gone faster but it was not a walk in the park either. In this example, the length and speed of this workout represent the external load and Paul’s perceived difficulty of the workout represents the internal load.
Understanding your external and internal load is key to not only achieving your optimal training outcomes, but also avoiding injury. Even if two people complete workouts with the same external load, if their internal loads differ then they will experience different results from their training. Even if two people complete workouts with the same external load, if their internal loads differ then they will experience different results from their training. Click To Tweet
You need to consider the following factors in order to know your internal load:
- Fitness Level
- Musculoskeletal Imbalances
- Current Injuries
- Previous Injuries
For example, if one runner has lingering, moderate quad soreness from a past workout while another runner has no current soreness or injury, the external load of a long run may be the same for both athletes, but the runner with the lingering soreness may feel like the workout was much harder and need longer to recover, while the runner with no issues may be able to recover from the run more easily.
Your internal load helps to determine the external load your body can handle. Some athletes may think they can rapidly increase mileage with no detrimental effects, but this is not the case. If one person cycles up to 50 miles a day and another only cycles a maximum of 40 miles, then the external load of a 50 mile ride on the person who normally cycles less may be much more taxing than a 50 mile ride on the person who normally cycles more.
Since external and internal training load combined lead to training outcomes, both should be evaluated in order to prevent injury. Increasing your external load without accounting for your internal load will lead to injury.
Tracking Your Workload to Prevent Injury
Tracking your workload can help you reach and maintain your optimal load to gain fitness while reducing injury risk. You can try it out and see how your body responds to workouts with higher loads and lower loads over the course of weeks and months. You may be surprised by what you find! Then, you can choose and adapt a training schedule with loads that work best for you in order to keep your body injury-free. And if math isn’t really your thing, the Fathom App is an easy, free tool to track and manage your workload, plus you’ll get custom pre- and post-training activity recommendations that help your body adapt and recover from those loads. Tracking your workload can help you reach and maintain your optimal load to gain fitness while reducing injury risk. Click To Tweet
Calculating load should take you less than 60 seconds. To find your workload (reported as Work Impact or WKI), multiply the duration of exercise by RPE (rate of perceived exertion).
Rate of perceived exertion represents how hard you think you have worked in your training session. It’s on a scale of 1-10 ranging from no exertion to maximal exertion.
Studies show that it is most accurate to record your RPE 15-30 minutes after the completion of your workout. That way, you have a clear recollection of your workout and exertion level.
For example, if you ran for 60 minutes and rated your RPE as a 6, your training load would equal 360 WKI. The next day if you ran for 90 minutes and rated your RPE as an 8, your training load would equal 720 WKI.
There is not one workload number you are aiming for day after day. Your training load fluctuates depending on your workout. A longer, more rigorous workout means a higher training load, while a shorter, easier workout correlates to a lower training load. You need both types of workouts to increase your speed and strength and allow your body to recover. This optimizes your fitness.
After each workout, calculate and record your workload. This can be easily done in an excel or google sheet, but do what works for you. Then you can begin to track your workload trends.
Acute and Chronic Workload
As you continue to track your workload consistently, you can analyze your 7-day (acute) and 4-week rolling (chronic) average workloads to understand your overall workload trends and patterns. This allows you to see how your weekly load compares to your more long-term average. If there is an unplanned spike or dip in training one week, make adjustments to ensure you achieve your workload goal the next week
Properly managed high chronic loads actually increase injury resilience in adult athletes. Part of preventing injury is having a strong, resilient tissues to protect yourself, and having a high chronic load helps to build your strength.
A well-trained athlete can accept a higher chronic load than an average athlete. This is why a novice athlete and an experienced athlete should have different workloads; for novices to prevent injury and for experienced athletes to reach their training goals. It’s also why someone who has never worked out before should not jump into an advanced training plan.
Tracking your load is a great start to understanding how your body responds to the physical stress of exercise. The next step in optimizing your fitness is learning how to manage it. To do this, you’ll want to track your acute:chronic workload ratio (ACWR).
Acute:Chronic Workload Ratio
A higher Acute:Chronic Workload Ratio (ACWR) means that your acute workload (your 7 day average) is much larger than your chronic workload (the average of the last 4 weeks). A lower ACWR indicates that your acute workload is more similar to your chronic workload (which is what you’re aiming for).Tracking your ACWR over time will help you to see the trends of your training load.
There are ACWR ranges associated with injury risks, determined by research on various populations.
- 1-1.3 ACWR is ideal and low injury risk.
- 1.3-1.5 ACWR is high with moderate injury risk.
- 1.5+ ACWR is very high and is typically a very a high injury risk zone for most of the population.
As helpful mental hint, an ACWR of 1 means the past 7 days workouts have been at the exact same load as your 4-week, chronic average. An ACWR higher than 1 means that you’ve had a harder week than average.
To maintain your fitness level, you generally want a consistent load from week to week. This will help to ensure you are training safely and avoiding injury. Definitely keep in mind that these ACWR ranges should serve as a guide, not the end all be all. Always listen to your body first, look to these numbers second. Find what works for you.
Safely Increasing and Decreasing Your Workload
In order to make progress in reaching your fitness goals, you may want to increase your workload by adding on miles or speed work to your training. You are most prone to injury during these periods of changing training loads. Carefully track your ACWR during these times so that to help avoid injury and stay within a sustainable training zone. Be careful not to increase your workload too rapidly. If you do so, your injury risk can increase, not just for that day but you may be more susceptible for several days following the spike. This is largely due to the time it takes for your body to recover from unaccustomed loading. If this happens, aim to keep your ACWR less than or equal to 1.1 for the following 7 days or so to reduce your injury risk.
After a race to recover or due to severe soreness or injury, you may want to decrease your load. If you are decreasing your load, try to keep your weekly ACWR drop above .8. Otherwise, you’re likely to increase your load at a moderately high risk level when you do return to your prior training habits.
Finding Your Optimal Acute and Chronic Workloads
Optimal acute and chronic workloads support progressing towards fitness goals and preventing injuries. But how do you determine what those numbers are for you? The best way is to track your workload and be in-tune with your body! The good news is you have now learned how to track your workload, so now you just need to learn how to gage your body’s needs.
To be in-tune with your body, consider variables such as soreness, previous and current injuries, illness, fitness levels, and prior training experience. You may need to adjust your training load based on these factors, even if you are within a proper ACWR range. For example, if you planned to go on an 8 mile run but your quads are really sore from your workout the day before, you might shorten your run or decrease the speed. Or, if you were going to do a track workout but have a cold, you might do every other interval to ease your breathing. Things don’t always go according to plan, and that’s ok as long as you adjust to the given circumstances. Taking it a bit slower now is always better than being sidelined with an injury later. To be in-tune with your body, consider variables such as soreness, previous and current injuries, illness, fitness levels, and prior training experience. You may need to adjust your training load based on these factors, even if you are… Click To Tweet
One way to become better attuned with your body’s needs is by journaling. Dedicate a notebook to tracking your workload and recording how you feel before, during, and after your workouts. The entries do not need to be very long, just straight and to the point. Fathom recommends the following format:
June 26, 2019
Workout: 3 x 1 mile repeats at 7 minute pace with a 2 mile warmup and 2 mile cooldown on the trail (~8.5 min pace).
Internal assessment before: I ate well yesterday but didn’t sleep very well last night. I feel pretty well hydrated. I do not have any soreness or pain and feel recovered from my run yesterday. My stress levels are not high either.
Internal assessment directly after my workout: It was definitely difficult! I would rate it an 8, but I was expecting it to be more like a 6. Today even my warm-up felt like a 5. This could be due to my poor sleep last night. On the second interval, my right calf tightened up. Definitely need to do some stretching later.
- Workout RPE = 8 * 21 min= 168 ,
- Warmup & cooldown RPE= 5 * 34 min = 170
- Total Session RPE= 338
Internal assessment a few hours after my workout: My right calf feels a lot looser after doing some stretches Fathom suggested. I need to monitor this during future workouts and keep strengthening and stretching. Although my workout was harder than I expected today, I think I should be fine to do my 5 mile recovery run tomorrow as long as my calf does not worsen. I will continue to monitor this soreness!
If you don’t like journaling, you could use a free app like Strava, make notes on your phone, or create an excel sheet. Find what works best for you and your schedule. It’s not so much about how you do it, but that you do it.
Taking 5-10 minutes a day to do this can make a big difference as reflecting on your workouts and personal needs will help you to take better care of your body, especially if you are training for a race or a personal goal. This will allow you to see on paper how you respond to different modes and intensities of training, rather than relying on faint memories and guesses to guide your training program. Using this information, you can determine the volume and intensity of exercise that is best for you. You may find that you need to decrease your load, that your body would benefit from a steady increase in load, or that you should just maintain your current load.
Then, the only thing left to do is implement these changes and kick these injuries. This will lead to more time training, nurturing friendships, and following your passion. After all, isn’t that why you do what you do? And remember, Fathom is here every step of the way to help you. Go get it, we believe in you!
To learn more, check out the following sources:
- Running Fact Sheet, Sports Medicine Australia: https://sma.org.au/resources-advice/running/
- Impact of Training Load on Injury Risk and Over-Training & Over-Reaching, Dr. Barnett S. FrankSports- and Recreation-related Injury Episodes in the United States, 2011-2014, Yahtyng Sheu, Ph.D., Li-Hui Chen, Ph.D., and Holly Hedegaard, M.D., https://www.cdc.gov/nchs/data/nhsr/nhsr099.pdf