For a non-contact sport, distance running has a pretty high incidence of injury. A recent review paper listed the rate of injury anywhere from 19.4% to 79.3%! While there is debate as to the causes of running injuries, training error is one of the most frequently cited issues.
Even diligently sticking to a training program may in itself be a training error. While many programs follow a schedule that gradually increases volume and/or intensity, it doesn’t mean that schedule is the one best suited for a particular runner on any given day.
External & Internal Load
Most runners track their training programs via old school pen and paper logs or some version of an electronic/online tracker.
Using GPS watches, smart phone apps or other devices gives you an accurate and valid measurement of what is called external load – distance, pace, elevation change, and so on; factors that quantify your training stress that are outside your body.
A second type of load is called internal load. This includes variables such as hours of sleep, resting heart rate, sleep quality, exercise heart rate, perception of effort, various biochemical markers, heart rate variability, mood, fatigue and other measurements of bodily functions.
Keeping track of external load is one major element of a well designed program that includes injury prevention. But many runners neglect monitoring their internal load. If they do record any of the internal load variables, exercise heart rate is the one most often measured.
The International Olympic Committee released a consensus statement earlier this year highlighting the importance of monitoring both types of load. The authors of the paper wrote:
Monitoring athletes is fundamental to defining the relationship between load and risk of injury…This includes accurate measurement and monitoring of not only the sport and non-sport loads of the athletes, but also the athletes’ performance, emotional well-being, symptoms and their injuries. [my highlight]
The benefits of scientific monitoring of athletes include explaining changes in performance, increasing the understanding of training responses, revealing fatigue and accompanying needs for recovery, informing the planning and modification of training programmes and competition calendars, and, most importantly, ensuring therapeutic levels of load to minimise the risk of non-functional over-reaching (fatigue lasting weeks to months), injury and illness.” How Much is Too Much? (Part 1)
The Importance of Internal Load
Training is a stress to the body from which it needs to recover. Recovery makes the body stronger and more resistant to a particular stress (i.e. training).
Most training programs are based on the principle of progressive overload, meaning they have to get harder over time to keep forcing your body to adapt. As every runner knows you can’t keep running the same distance or intensity if you want to improve your fitness.
But exercise is only one of many stressors in your life. Your life outside of training will greatly influence how you recover. Further, training not affects your physiology it impacts your psychology as well; it can be a mental stress in addition to a physical one.
While there is a general timeline of how long it takes your body to adapt, every runner is unique. So while a group of runners may follow the same program, they will all adapt to it at different rates. The external load may be the same but their internal loads may be vastly different.
Even for any individual runner, how their body responds to stress can vary greatly depending on their age and circumstances. How you adapted to exercise in your twenties is different to how your body will adapt in your 40’s, 50’s and beyond.
Training for a marathon when you don’t have kids, have a secure job and social life is vastly different from training for a marathon when you have a new baby, have moved to a new city and started a new job. External loads may be the same but your internal load will be very, very different.
(Training for a marathon in the second case isn’t recommended.)
Knowing your recovery and internal load will let you know when and if you need to change a program or workout. If you’re under-recovered a particular workout may be too much. Or it may be a series of workouts that progressively wears you down and then one day, a given workout is the proverbial straw that broke the camel’s back and you wind up injured or ill.
As the authors of the IOC statement paper write:
Whereas measuring external load is important in understanding the work completed and capabilities and capacities of the athlete, measuring internal load is critical in determining the appropriate stimulus for optimal biological adaptations. As individuals will respond differently to any given stimulus, the load required for optimal adaptation differs from one athlete to another. For example, the ability to maintain a certain running speed or cycling power output for a certain duration may be achieved with a high or low perception of effort or heart rate, depending on numerous inter- and intra-individual factors, such as fitness and fatigue.” How Much is Too Much? (Part 1)
I should note that while this was a paper authored by the IOC, the review included studies involving athletes of all levels from recreational to elite. So don’t assume that tracking internal load is only for high level runners.
Monitoring Recovery for the Average Runner
Now that we’ve established why it’s important to monitor internal load and recovery let’s look at how the average runner can easily monitor this.
Elite runners have a team of professionals behind them. They usually have access to therapists, doctors, coaches, athletic trainers and so on. This includes access to monitoring devices and protocols that aren’t cost-effective or convenient for the average runner.
Fortunately there is an easy, cheap and convenient way to monitor internal load for everyone. A recent review paper looked at self-reported measures versus objective measures of athlete well-being.
Objective measures includs attributes such as blood markers, resting heart rate, exercise heart rate, oxygen consumption and so on. Subjective measures refers to items such as mood, perceived stress, etc.
The authors of the review paper state:
Subjective measures reflected acute and chronic training loads with superior sensitivity and consistency than objective measures.
This review paper provides further support for practitioners to use subjective measures to monitor changes in athlete well-being in response to training. Subjective measures may stand alone, or be incorporated into a mixed methods approach to athlete monitoring, as is current practice in many sporting settings.” Monitoring the athlete training response…a systematic review
A simple daily questionnaire can provide you with reliable information about your internal load and recovery.
I use a service called Training Peaks for coaching runners online. In addition to easily allowing us to view their programs and training I also have them answer a few basic questions rating sleep quality, soreness, stress, fatigue and mood.
This helps me determine if we need to change a particular day’s workout and gives me a good snapshot of their internal load. The questions I use are based on a study looking at monitoring rugby players between games.
Why I Prefer Tracking Subjective Measures
There are a few reasons I prefer tracking subjective measures to objective ones. Of course you can do both but for recreational runners here’s why I think you’re better off recording subjective traits:
Easy to Understand
A few years back I tracked something called heart rate variability or HRV for short (I’ll explain what it is in another article). For now all you need to know is HRV is an objective measure of internal load.
It sometimes correlated to my training schedule and subjective measures but other times it didn’t line up. There were days when my HRV score would be “good” but I would feel like crap. Likewise, on other days I might feel great but my HRV score would be down.
That’s not to say you can’t use HRV or other objective measures. But you really need to understand what it is they’re showing you. A doctor is able to interpret your lab results but most patients can’t make heads or tales from their blood tests.
Subjective measures don’t require specialized knowledge to understand.
Focus & Mindful Training
Asking yourself questions about how you’re feeling brings about a mindful practice to your training.
Instead of simply logging in the miles required in your program, you have to think about how those miles are affecting you. Sometimes injuries do occur “out of the blue” but in many instances injuries are preceded by warning signs. Tracking internal load makes it harder for you to ignore those warning signs. It allows you to take action before a warning sign becomes a bigger problem.
Many distance runners are tightly focused on hitting specific training targets each week. But a training schedule assumes everything is going well and you’re ready to tackle any given workout. The reality is you may well not be ready for a 20 mile run or a hard tempo effort that day.
Cutting your run short or dropping the intensity may do more for your fitness than trying to meet a target that’s too high for you on that day.
Many objective measurements require special equipment. Some are as simple as an app but others require devices that can be expensive. A simple questionnaire doesn’t need fancy equipment. If you’re reading this you most likely have a desktop computer, laptop, smartphone or tablet capable of using a spreadsheet. But in a pinch you could also use pen and paper.
For these reasons, I think subjective measurements are the way to go for most recreational runners.
Putting This Into Practice
I’ve put together an easy to use spreadsheet you can try yourself that uses similar questions.
(I have sport scientist/S&C coach Patrick Ward to thank for this. I copied this spreadsheet from one he had put together.)
Each day you rate five factors (quality of sleep, fatigue, muscle soreness, stress level and mood) on a scale of 1 – 5 along with your hours of sleep. This will give you a daily score and provides you with an easy, convenient way to monitor recovery and internal load that takes less than one minute each day.
Here’s a snapshot of a few days of tracking these items:
On any given day you’ll see how well you’ve recovered and how ready you are for that day’s workout. The daily score cell will turn red if you score low, go yellow to note caution and be green if you have a high score.
Let’s say you score low one day and a red flag comes up. During your warm-up, pay attention to how your body is responding and progress into a hard workout with caution.
For example if doing track repeats, start with a pace that’s a bit slower than you had planned. If everything is feeling good, increase the pace with each successive repeat until you’re at your goal pace for the workout. If however you feel something is off (i.e. a particular muscle tightening up, unable to hit a target pace, etc) you can back off or cut the workout short.
But it’s not one particular day that you’re only concerned about. Everyone has bad days. And a one off bad day (i.e. a crappy night’ sleep) may not be reason enough to change a particular workout such as a long run or hard interval workout.
You’re looking for trends; if you see multiple days in a row of inadequate recovery then you’ll want to adjust your training so the external load matches your internal load.
You’re also looking at the individual categories and noting if there’s one that scores low frequently. If so, you can then focus on taking steps to improving that area i.e. if sleep quality is often low, look at strategies and help in getting better sleep.
Try My Recovery Tracker
You can download the recovery tracking sheet as well as an instructional video by signing up to my newsletter here.
Or you can build it out yourself. You can use the same attributes as I do or choose another set. But whatever you do, I highly encourage you to keep an eye on your internal load and recovery.
You’ll race better and stay healthy by knowing when and if to make changes to your training program.
- Runners should track external as well as internal training loads.
- Monitoring internal load & recovery is important for runners of all levels.
- Subjective variables are as valid as objective measurements.
- For recreational level runners, subjective measurements are easier to use and make your training more mindful.
- Use my recovery tracker or develop your own to monitor recovery and internal load.