External vs Internal Training Load: Is Monitoring Load on the Bar Enough to Ensure Progress?
By: Dr. Cody Haun
“Am I properly progressing my training and how do I know?”
“What exactly is the principle of overload and how does it apply to me?”
Proper answers to questions like these are critical to a productive training process absent of or limited in the occurrence of injury. Although more writing on this is sure to follow, I’d like to start by clearly defining some terms and discussing the difference between external and internal training load to help begin to answer these and related questions in future posts. So, this post is meant to be a concise overview that provides some key operational definitions and brings attention to the difference between external and internal training load in order to get us started. I’ll then conclude with some practical variables to consider monitoring to help you start putting these concepts to work for you.
The Principle of Progressive Overload denotes that training should increase in difficulty, in some way, over time to continue making progress. To target this discussion, we’ll focus primarily on resistance training although these concepts also apply to other types of training (e.g., endurance training, skill training, etc.). The term “Progressive” denotes a gradual increase while “Overload” denotes a load comparatively greater than previous loads. For example, last week let’s say you lifted 200 kilograms for 5 reps and then this week you lifted 205 kilograms for 5 reps. Voila! Proper overload achieved!
But, is it really that simple?
Was a 5 kg increase sufficiently more difficult?
Would a 10 kg increase been more effective?
What if your technique was worse this week?
What if you had done 200 kilograms for 7 reps instead of 205 kilograms for 5 reps this week (i.e., same load, more reps)?
What if this week you were disproportionately fatigued from the workout compared to last week?
Will the adaptive outcomes be the same?
Justifiably, this leaves one asking: “Well, then what characterizes proper application of overload exactly?”. Let’s first define and examine some terms for the purpose of this post and future discussion.
a.) external load– the physical workload completed by the athlete during a training session, practice, or competition independent of an athlete’s internal responses.
b.) internal load– the relative manner in which the athlete physiologically and perceptively responds to a given physical workload.
c.) non-functional overreach– a short-term decrement in performance due to training with no eventual improvement in performance.
d.) functional overreach– a short-term decrement in performance due to training with an eventual improvement in performance.
e.) overtraining syndrome– a long-term state of suppressed performance capability due to prolonged non-functional overreaching.
To quickly revisit the term overload, overreach can be considered a synonym for the purpose of this post. Both concepts denote a sufficiently difficult training stimulus that disrupts “homeostasis” (e.g., relative stability of physiological systems). Critically, it is the magnitude of this disruption necessary for improvement that we are concerned with as athletes and coaches. That is, we want to get the training dose just right to maximize adaptations and eventual performance.
So, how do we go about doing that?
In my opinion, this is primarily achieved through monitoring the dose-response patterns of the training process closely. That is, clarifying what performance outcomes result from various training doses and individual athlete responses. Keep reading!
As defined above, overreaching has been divided into categories of “functional” and “non-functional” in the SportScienceliterature. Briefly, functional overreaching involves a short-term decrement in performance which eventually leads to improvement, while non-functional overreaching does not. For example, you lift weights, cause a disruption of muscle homeostasis (e.g., structural damage, increased metabolism, etc.) worsening its temporary force production capability, and, with proper recovery, eventually your muscle gets bigger and/or stronger. This is an example of functional overreaching on a short-term scale. Non-functional overreaching wouldn’t result in an improvement in muscle properties.
With this in mind, elucidating the appropriate dose of training to result in the desired adaptive response can be achieved through appropriate examination of both the externaland internalload of training, and the eventual performance or body composition response. To be clear, monitoring training data and advanced data analysis are largely unfruitful unless boththe dose of training andthe response are closely examined.
Let me give an example to make more sense out of this.
An athlete squats 200 kg for 5 sets of 3 reps (15 total reps).
This means the athletes volume load or “tonnage” for squats during this training session was 3000 kg (i.e., 200 kg x 15 total reps).
This is an example of an externalload calculation.
The athlete reports perceiving they could have performed 2 more reps for each set on average with good technique, or an 8 rating of perceived exertion (RPE) on a 1-10 scale.
This perception score is an example of an internalload calculation.
Other examples could include physiological data like heart rate, muscle protein synthetic responses, gene expression, etc. Obviously, some are more practical than others in typical settings but the example stands nonetheless. A future aim is to develop non-invasive methods of assessing internal load in a valid and reliable manner as many physiological assessments require collection of tissue or blood, and of course this isn’t always feasible.
Let’s say in a following block of training, the athlete performs the same squat volume but reports the ability to perform 4 more reps per set on average, rather than 2, or a 6 RPE.
This indicates an improvement and is one example why capturing BOTH external AND internal load is critical to better understand adaptive responses and make more informed programming decisions. That is, had the internal load calculation not been made, one might incorrectly conclude a lack of progress.
In addition, a predicted 1RM can be calculated using these data, and visualized over time. A cool feature of APLYFT’s app is that this is done automatically and can be visualized over time.
Monitoring external and internal load data can be an arduous process and I’m not claiming this is easy. This requires diligent data entry and management, regular athlete-coach communication, and consistent training and physiological monitoring procedures over relatively long periods of time for confident programming decisions. To segue briefly, this is where tools like APLYFT shine and why I’m onboard the APLYFT train. For years, I’ve used both simple and elegant spreadsheet-based monitoring and analytic procedures (and still do for certain things), but APLYFT conveniently allows programming and monitoring to occur in one place using a mobile application and online coaching portal and coaching app where I can easily program, analyze, and chat directly with clients to make this process more efficient. APLYFT’s mobile application allows select internal and external load data to be easily entered from the palm of an athlete’s hand, and these data are archived in a database for analysis and use in monitoring dose-response relationships and therefore can influence eventual programming decisions. Further, this method better ensures that athletes will actually enter data, and coaches can be confident that data are stored in a database for analysis without making either step unnecessarily complicated or requiring copious amounts of paper recording methods since the app is mobile and simply convenient for clients to use.
APLYFT’s analytic capabilities in the coach’s online portal can serve to visualize dose-response relationships and can allow eventual postdiction (i.e., understanding why something happened based on historical data) and prediction (i.e., estimating what will happen from a programming decision) of performance outcomes with certain degrees of confidence. For many coaches and athletes, one of the primary barriers of performing detailed athlete monitoring using both internal and external training load data is data storage and management (since many people use individual spreadsheet file sharing, or hard-copy reports). Employing a method that uses advanced mobile technology really eases the burden and is a solution to this barrier, which is why I use APLYFT. Future directions in store are exciting, including advanced data visualization tools and convenient programming tools in the coach portal to minimize some of the monotony of programming to focus on more of the important stuff. In addition, allowing payments to be processed easily and securely through the app and having a chat feature allowing audio, video, and storage of photo, video, and audio files are additional selling points for me.
To round this up until next time, I’d like to provide a table from Dr. Shona Halsonthat can help guide your consideration and selection of internal and external load variables pertinent to your client or sport. In following posts, I plan to more clearly describe how APLYFT features can be used to achieve monitoring, programming, and eventual performance goals for specific training endeavors.
Thanks for stopping by!
“I’m a scientist first and a coach second. I have a passion for positively impacting the lives of people through providing critically thought-out, data-driven, scientifically-sound nutrition and training programming services that equip individuals to successfully achieve their performance and/or physique goals. I seek to offer the best service within my power and I am confident, given my background, education, experience, and relentless pursuit of knowledge pertaining to human physiology and the training process, that I can provide you with programming to realize great results. Feel free to contact me with any questions.”
Cody Haun, PhD, MA, CSCS
-APLYFT Science Consultant