The importance of a training diary

An article written by Sophie Herzog, Øyvind Sandbakk, Trond Nystad and Rune Talsnes

Successful athletes and coaches embrace that meticulous attention to training planning, execution, and debriefing through documentation and analysis is critical to achieve peak performance. One of the most effective tools for managing these aspects is a training diary. It serves as a point of departure for planning, monitoring, documentation, and communication around the training and development process.

Example insight for a training overview using Bestr (https://www.bestr.no/)

The Essentials of Training Documentation

To safeguard your athletic development, it is important to consistently record and quantify relevant information regarding your training, testing, recovery and overall well-being (including physical and mental health). Cultivating the habit of daily documentation ensures that no critical detail is overlooked or forgotten, and trends can be recognized early. The more accurately you document, the more valuable your training diary will be for analyzing and planning your training process.

A training diary is a written record, typically organized by date, that captures the details of an athlete’s daily training sessions, associated comments, as well as stress and recovery metrics. While training diaries traditionally used to be handwritten, they have largely transitioned to digital formats, capturing a broader range of (data) inputs and allowing more sophisticated analysis features (more on that later). A comprehensive training diary includes not only objective metrics but also subjective inputs of the athlete that add contextual information and enrich the “raw” data. The table below outlines a number of variables that are often logged in a training diary and can be used to monitor athletes training load as well as fatigue and recovery[i].

Table 1: Monitoring parameters in a training diary.

Training data can be categorized into two main types: external load and internal load measures. External load refers to measurable factors like speed, pace, and power – objective metrics that quantify the physical work performed. On the other hand, internal load reflects the body's response to this work and can include both objective measures, such as heart rate and lactate levels, and subjective metrics, like Rate of Perceived Exertion (RPE).

While both types of data have their strengths and weaknesses, understanding the interplay between external and internal load metrics is one of the most crucial puzzle pieces for a comprehensive evaluation of training.

Some athletes prefer to import objective data such as heart rate directly from a smart device (e.g., sport watch, bike computer or heart rate monitor), while others manually upload and log each session. Whichever method you choose, it’s crucial to ensure that the data collected is accurate and correct, before placing too much trust in objective data. For example, have you ever gone for a run and realized afterwards that you were “walking on water” according to your GPS, or that your heart rate monitor displayed a single, continuous value despite varying efforts? Measured data is certainly not always perfect and shouldn’t automatically be considered a “fact”. Regularly reviewing your recorded data and staying familiar with your input parameters can be a valuable habit.

Furthermore, if you choose to upload data automatically, ensure your intensity zones (e.g., heart rate, power or pace zones) are accurately defined. Furthermore, when you or your coach are interested in your training intensity distribution, it’s important to recognize that there are different approaches to quantifying intensity, such as the time-in-zone method versus the session goal approach, which can yield different interpretations[ii]. For example, using heart rate to determine time spent in specific intensity zones can underestimate the external work (e.g., power or speed) done during interval sessions, particularly those involving short, highly intensive intervals. This underestimation occurs due to the lag in heart rate response, which can result in less time being recorded in higher (internal) intensity zones than was actually spent performing high-intensity work.

As mentioned in a previous blog post, metrics like heart rate or lactate can also vary significantly depending on the modality (e.g., running versus cycling) and environment (e.g., heat or altitude). Therefore, it’s crucial to add contextual information to each session via comments, as the “naked” numbers often don’t tell the whole story.

Subjective information, while not measurable or verifiable as “the truth”, also needs calibration. For instance, if an athlete says, “I always have a high heart rate during easy runs; this is normal”, they may be executing “easy” based on their personal experience rather than established standards. This subjective measure might not align with what is typically considered easy in literature or when compared to objective metrics like heart rate or lactate levels.

Similarly, if an athlete has been struggling for a long time, their definition of “feeling good” or “normal” might also need to be calibrated. Therefore, it is important that athletes learn to calibrate their subjective experiences against objective references to ensure they’re on the right track.

The Value of a Training Diary

A training diary is an invaluable tool for both athletes and coaches. When used systematically over time, it provides a detailed history of how an athlete has responded to various training and recovery stimuli. These comprehensive insights are essential for tailoring future plans to each athlete’s individual needs. Since every athlete is unique and each sport has its own demands and challenges, understanding these individual nuances is key to effective training. To plan future training, one must first analyze and understand the training which has been done in the days, weeks, months or years before. Detailed past records (of the same athlete) are data “treasures” and can be used to create informed training plans with higher effectiveness and likelihood of success.

A training diary becomes especially important when an athlete is experiencing frequent illnesses, injuries, or unexplained underperformance. It is also invaluable in early identifying symptoms or indicators of underperformance such as overreaching or relative energy deficiency[iii]. By systematically quantifying training, testing and performance data, coaches and athletes can pinpoint potential causes of these issues and take proactive steps to prevent their reoccurrence. Just as a compass and a map guide you through unknown territory; a well-maintained training diary helps you navigate the path to peak performance.

Training Load Management in Training Diaries

Different training platforms use different variables to prescribe, describe and quantify training load. Training load has been described elsewhere[iv] as the “cumulative amount of stress placed on an individual from a single or multiple training sessions […] over a period of time.” As mentioned above, training load is often divided into two categories: external training load – the physical work prescribed in an athlete’s training program – and internal training load – the psycho-physiological response to this work, which reflects the “dose” of training received [[v]]. Although these concepts sound reasonable, neither internal nor external training load has a universally accepted gold standard measure, and the validity of these metrics is likely to be context dependent. For a deeper dive into training load, Passfield et al. have written an excellent review on this ambiguous concept[vi].

Most commonly used training platforms rely on key metrics such as Functional Threshold Power, Pace or Heart Rate (FTP)[vii] to establish training intensity zones and to calculate training load. While these metrics can be valuable when their major input values (FTP) are accurate and up-to-date, it’s important to also recognize the limitations of this system. For example, when training intensity and zones are based on a single value like FTP, the accuracy of your entire training plan and its analysis depends on the precision and currency of that value. How recently was your FTP updated? How accurate was the test, especially if it was derived from a shorter effort[viii]? Relying too heavily on one parameter can be risky, especially if you don't regularly update it or understand how it may vary due to factors like environment (e.g., heat, cold, altitude), equipment (e.g., differences between a time trial bike and a road bike), or other contextual elements.

This underscores the need for combining external and internal, objective and subjective measures. Every metric has its strengths and weaknesses, and over-relying on a single measure most likely leads to missing out on other important information. Therefore, the most effective approach consists of a multi-parametric system integrating information from different monitoring tools and systems and ensuring that they are based on accurate inputs and proper calibration. This balanced combination of diverse metrics yields the best results over time.

The Role of Technology in Training Documentation

Some training platforms, use algorithms and artificial intelligence to calculate metrics like fitness, form, fatigue, load and other values. While these metrics can be helpful if used correctly, we would urge athletes not to rely completely on such “scores”, as they can give a false sense of control over the athlete’s performance and/or drive the athlete crazy. The “objective metrics” are often based on a single/few values which must be recorded correctly, for the calculated values to be accurate. Subjective measures also have their flaws, as they are highly dependent on the perception, definition and accuracy of the person writing them down.  The body is a highly fine-tuned “machine”, an extremely complex system which we have not entirely “decoded”. But your body will give you a better “real-time” feedback than any performance chart. If you feel in “form”, this is usually more correct and valuable than the “form” curve in a performance chart. Since not all athletes are trained to provide accurate subjective data, we believe it is a good idea to use both, subjective and objective values and learn how to align them over time. It is important to be mindful of dissociation or contradicting indicators and learn how the different metrics in your monitoring system are standing in relation to each other. Understanding and using this informative “matrix” forms the foundation for decision-making and future training plans.

Flexibility in Training Plans, Analysis and Communication

Training planning and analysis are continuous and iterative processes. To develop effectively, athletes and coaches must learn to observe, assess and adapt the training. This approach is not an exact science, but rather a blend of art and science, where internal and external metrics are integrated with a training philosophy to create a plan that both coach and athlete believe in. The goal is to design a training process that is not only effective but also tailored to the realities of both training and life.

“The biggest mistake is not to have a plan, but the second biggest mistake is to follow the plan too stubbornly.”

A key principle in effective training is the ability to adapt plans as needed. Sometimes, the athlete won’t be able to execute the planned training. Many coaches and athletes see this as something negative. However, this is not always the case. The key is to understand why this happens, so that future plans can better reflect reality.

In addition to a certain degree of flexibility, it is also essential to analyze the training you have completed. Effective training is a process of continuous evaluation and adaptation. After implementing a new training stimulus, it is vital to analyze its impact: Is the athlete improving? Is the stimulus sustainable? Can the progress be maintained? Is the athlete enjoying the process? Could the approach be optimized? This trial-and-error method is necessary but must be managed carefully. Making too many changes at once or frequently altering training stimuli can obscure what’s truly effective, leading to confusion rather than clarity. The key is to strike a balance: allow enough time to observe the effects of changes but be ready to pivot when necessary.

There is a saying that goes “You never step in the same river twice”. It means that everything, including yourself, is in a constant state of flux. We are living in a dynamic environment and the ability to change and be adaptable is important. Training programs should be flexible, adapting to the athlete’s evolving needs and circumstances.

This adaptability requires trust and strong communication between the athlete and coach. While the coach brings theoretical knowledge and practical experience, the athlete’s input – based on their perceptions, fatigue, mood and daily experiences – is invisible to the coach, but crucial for shaping an effective program. Without this exchange, the training plan risks becoming too rigid and idealistic, which may lead to success in the short term but often comes at the cost of not allowing a sustainable, long-term development[ix].

Regular analysis and communication are essential components of sustainable, long-term development. In this process, both coach and athlete should feel responsible to participate. It is good practice to review your training at the end of each week, becoming aware of your progress, stagnation or shortfalls, and use these insights and learnings to optimize training prescriptions for the week(s) to come. Writing a short review or comment at the end of each week helps you and your coach to better understand and adjust the training load of the coming weeks, ensuring that you can adapt optimally.

For athletes working with a coach, regular meetings to discuss progress and to continuously update or adjust the plan are essential for a successful development process. We recommend short weekly check-ins, more detailed discussions after each training block and a comprehensive analysis at the end of each season. These sessions help to build a “common language”, to align expectations and ensure that the training planned is based on reality and not wishful thinking.

Many athletes rely heavily on their coach to handle the planning and analysis, but this approach can be limiting. A coach can’t “feel” what the athlete is experiencing, which is an essential component for making a good plan. While it may be tempting to delegate all planning to the coach – believing they are able to provide the “perfect recipe”, finding the process boring, or simply wanting to avoid the mental effort – these are not valid reasons to disengage. Good coaches require their athletes to be invested in the process. For a coach, creating a plan is relatively quick work, but mentoring and guiding an athlete’s development requires time, effort, and ongoing collaboration.

The most successful coaches and athletes know when to stick to the plan and when to adjust it. Rigidly following a plan and prioritizing box-checking over training quality and optimizing development will lead to suboptimal results, diverting from the overarching goal: progress – which is rarely linear.

Integrating Physiological Tests with Training Diaries

In the next blog post, we will discuss various easy-to-administer physiological tests that provide information on the athlete’s state and insights into how the athlete has responded to the training (or recovery). Calculated values can always be used to support decision-making. However, we believe that the best approach is to use results of standardized tests in combination with data and subjective information from the training diary to ensure an accurate analysis of the training process.

Conclusion: Pay Your Success “Insurance”

Training is more than just executing what is on the plan. Reflecting on your training and documenting your training process carefully and systematically is crucial to ensure that you are continuously developing, learning from the good and the bad and progressing towards your goals. If you are interested to learn more about how to effectively use a training diary, how to interpret the data and use it for guiding or adjusting your plan, get in touch for personalized advice.

[1] This categorical approach assigns the entire session into a single intensity zone with the assumption that the “goal portion” of the session primarily determines its impact as an adaptive signal and source of physiological stress. A categorical approach likely gives a realistic picture of the total training-intensity distribution (TID) over the long term and is frequently cited in the literature [ii].

[i] Halson SL. Monitoring training load to understand fatigue in athletes. Sports Med. 2014 Nov;44 Suppl 2(Suppl 2):S139-47. doi: 10.1007/s40279-014-0253-z. PMID: 25200666; PMCID: PMC4213373.

[ii] Sylta O, Tønnessen E, Seiler S. From heart-rate data to training quantification: a comparison of 3 methods of training-intensity analysis. Int J Sports Physiol Perform. 2014 Jan;9(1):100-7. doi: 10.1123/IJSPP.2013-0298. PMID: 24408353.

[iii] Stellingwerff, T., Heikura, I.A., Meeusen, R. et al. Overtraining Syndrome (OTS) and Relative Energy Deficiency in Sport (RED-S): Shared Pathways, Symptoms and Complexities. Sports Med 51, 2251–2280 (2021). https://doi.org/10.1007/s40279-021-01491-0

[iv] Soligard T, Schwellnus M, Alonso J-M, et al. How much is too much? (part 1) International Olympic Committee consensus statement on load in sport and risk of injury. Br J Sports Med. 2016; 50(17):1030–1041. PubMed ID: 27535989 doi:10.1136/bjsports-2016-096581

[v] Impellizzeri FM, Marcora SM, Coutts AJ. Internal and external training load: 15 years on. Int J Sports Physiol Perform. 2019; 14(2):270–273. PubMed ID: 30614348 doi:10.1123/ijspp.2018-0935

[vi] Passfield, L., Murias, J. M., Sacchetti, M., & Nicolò, A. (2022). Validity of the Training-Load Concept. International Journal of Sports Physiology and Performance, 17(4), 507-514. Retrieved Aug 23, 2024, from https://doi.org/10.1123/ijspp.2021-0536

[vii] https://www.trainingpeaks.com/learn/articles/an-introduction-to-trainingpeaks-metrics/

[viii] https://www.trainingpeaks.com/blog/performance-assessment-tests-for-cyclists-and-multisport-athletes/

[ix] Some ideas from: https://solaarjona.substack.com/p/cps-approach-to-training-and-health?utm_source=post-email-title&publication_id=1491162&post_id=147554671&utm_campaign=email-post-title&isFreemail=true&r=1z4sc8&triedRedirect=true&utm_medium=email