To kick of this marathon training series blog, we will talk about load monitoring. Training for a marathon or any long-distance running event requires careful management of training loads to optimise performance and reduce the risk of injuries. Load monitoring plays a critical role in achieving this balance and is relevant not only for those training for a marathon, but for all athletes and individuals performing their sport. Whilst too much or too little training load may contribute negatively to performance (overreaching/overtraining or detraining respectively), an optimal training plan can facilitate short & long term improvements in performance, health & fitness. As such, it is essential to monitor fatigue, fitness and performance to enhance training and adjust accordingly to optimise performance and reduce injury risk. In this post, we will delve into the intricacies of load monitoring, discussing what and how to monitor and the distinction between internal and external load.

Understanding External and Internal Training Load

Quantification of training load is generally split into external and internal load. External training load is described as the physical activity or work that is being completed. For runners, this is typically monitoring training volume (km), frequency, intensity (kph) and type. Internal load on the other hand, describes load that is intrinsic and represents an athletes physiological and psychological response to load. Such measures include oxygen uptake, heart rate, heart rate variability, heart rate recovery, blood lactate and rate of perceived exertion (RPE).

Put simply, for running athletes we can track not only our running loading but also monitor our response to such loadings. Why is this important?

Take the simple example below:

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Here we see an athlete who has completed 2 workouts per week for 4 weeks, tracking both distance and RPE. We can see that the rate of perceived exertion (RPE) for workout 1 progressively increased, as expected with the increase in km during workout 1 sessions. However, workout 2 which is a consistent 10km run, has progressively increasing RPE per week. Although the athlete is completing the same 10km distance per week, the athlete is perceiving this activity as progressively harder, going from a 4/10 (moderate) in week 1 to a 9/10 (really, really, hard) in week 4.

This simple example highlights that all load is not equal and that internal responses to external load can vary dramatically dependent on various factors such as fitness, fatigue, psychosocial fitness, and health to name a few.

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So How Can I Use this to Inform my Training?

The most simplistic method of increasing training load to minimise risk of injury is the ‘10% rule’. Although this is useful, an alternative method uses acute:chronic workload ratio from Tim Gabbett’s research. This involves monitoring your acute load (7 day) along with your chronic load (4 weeks). This and other research such as Bowen et al (2020) who tested this model in English Premier League football, highlighted the ‘sweet spot’ for reducing injury risk is a ratio between 0.8 to 1.3. Avoiding spikes that approach or exceed 2.0 was shown to reduce injury in elite footballers.

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For instance, lets have a look at my current workload management graph I am using for my own current marathon training:

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The black dotted lines in the graph above represent the 2 ‘cutoffs’ of 0.8 and 1.3 for acute: chronic workload ratio (ACWR). Load represents distance completed per session with 2 types of ACWR used. We can see that loading has been at that 1.0 ratio ‘sweet spot’ pretty consistently however recently loading increased, with the latest data indicating a ratio of 1.25, just below the 1.3 cutoff. Monitoring of recent changes to my running load along with assessing both internal load and psychological responses can ensure performance is optimal and injury risk is reduced.

Other Factors to Monitor: From Our Physiological Response, Mood and Aches & Pain

There are several other factors that are also worth monitoring to provide a holistic oversight into our response to training and running loads.

Physiological Response to Loading & Overall Physiology

Our physiological response to our running sessions, particularly heart rate (HR) data can be useful in monitoring the autonomic nervous system (ANS) response and long term changes/adaptations. The ANS is a component of the peripheral nervous system that regulates key involuntary physiological processes including HR, blood pressure, respiration and digestion. Of particular note are the following measures:

• Resting heart rate (RHR) - number of heart beats per minute whilst at rest. Indicator of long term fitness
• Heart rate variability (HRV) - the amount of time between each heartbeat which normally fluctuates slightly. Reflects how well your body can adapt to stress.
• Heart rate recovery (HRR) - measurement of your hearts ability to return to its normal, resting pace after a workout/activity
• Session average heart rate (sAvgHR) - average heart rate for the duration of the session. This can be analysed per heart rate zone.

Below is an example of how I use HR data to monitor acute changes and chronic adaptations to exercise or strain using the WHOOP.

As you can see, around the early to mid May period, my HRV was reduced compared to average and my resting HR was increased compared to average. During this period of time, contextual factors were also at play - recent 24hr+ flight journey and poor sleep along with changes to environment (cool to hot climate). These factors may have contributed to changes in HR measures. As a result, I reduced my running loads during this period to allow for recovery back to baseline.

Mood, Sleep & Stress!

An often overlooked aspect to monitor is mood and stress. How do you feel? Are you feeling fresh or exhausted?  Monitoring your mood and stress levels can provide insights into how these factors are influencing your external and internal loading. Evidence highlights that mental fatigue can impair endurance performance. Stress & mood may also be reflected in RPE scores. For instance, RPE may be increased as we perceive the same stress to be more difficult.

Sleep is also an important factor to monitor for an athlete. Inadequate sleep has been shown to increase injury risk, impair performance and increase your perception of stress. Sleep also has an influence on our intrinsic recovery, particularly deep sleep and rapid eye movement (REM) sleep where these 2 stages optimise physical and mental restoration respectively. Monitoring devices such as the WHOOP can assist in tracking, monitoring and optimising sleep routines to enhance recovery

Aches & Pains!

Aches & pains are a normal process at some points during training. That said, oftentimes minor ‘niggles’ are ignored and may potentially develop into an injury. Using a diary or an athlete monitoring form can be useful to monitor patterns and changes in these aches and pains to reduce the risk of injury. A niggle is likely more transient - minimal intensity of symptoms that may last one or two sessions. Consistent symptoms however that linger or are more frequently reproduced through multiple sessions should be addressed. Physiotherapy assessment may be appropriate to identify the source of pain, especially if any symptoms occur or effect every day activity.

Below is an example of some of the symptoms I reported during some of my runs last week - lower back (lumbar spine) ache pain. Because this was identified and noted, I incorporated some lumbar specific exercises and also reduced my total mileage and had a de-load week to manage symptoms. The long run I completed yesterday was pain free with no symptoms. To reduce the risk of any further niggles occurring to this area, I have incorporated a lumbar. hip & groin mobility and strengthening routine.

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Individual Specific Tests

Individual specific tests are key subjective and objective findings that are important to monitor during your training. This may be a variety of tests such as range of motion, strength (maximal and endurance), power testing and stability tests. This could also be based on areas of weakness of previous injuries whereby monitoring any signs of aggravation is important to reduce the risk of re-injury.

For instance, I personally have a history of hip joint pathology and as an early warning sign my hip internal rotation reduces significantly, influencing running mechanics and potentially leading to injury. I monitor hip internal rotation range of motion and combine this with other data to provide an indication of overload and when this drops significantly, I reduce my loading to avoid injury.

Useful Tools to Monitor Load for Running & Marathon Training

Here are some of the tools and devices I use to monitor my training loads - this is not an exhaustive list however it provides some insight into how I use multiple technologies to monitor and plan my training loads.

• Strava - running loading. This data is exported into a custom Excel template where I delve further into the data. I provide this on request for my clients.
• WHOOP - provides data and insights into my internal loading and sleep.
• Symptom diary - I use the comments section on Strava to make notes of any symptoms.

Final Comments

Load monitoring is a crucial aspect of marathon and running training, allowing athletes to optimise performance and reduce injury risk. By tracking both external and internal load, athletes can gain valuable insights into both their training and physiological responses. Tools such as training diaries, wearable devices, and objective assessments, can give athletes comprehensive data.

Moreover, monitoring other factors such as physiological responses, mood, sleep, stress, and aches and pains provides a holistic view of an athlete's overall well-being and readiness for training. By paying attention to these indicators, athletes can make informed adjustments to their training plans and reduce the risk of overloading or injury.

By incorporating evidence-based load monitoring techniques into your training regime, you can achieve optimal performance while minimising injury risk. Remember, load monitoring is not just about numbers and data; it's about understanding your body, listening to its signals, and making informed decisions to ensure long-term success in your running journey. Check out the great references and resources below to delve deeper into this topic and the latest research!

Stay tuned for more informative blog posts, where we will delve into other crucial aspects of marathon training, injury mitigation, and performance optimization.

Start monitoring your loads effectively and unlock your full potential as a marathon runner or athlete today. Inquire today about our high performance management services.

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References

Gabbett, T. J. (2020). How Much? How Fast? How Soon? Three Simple Concepts for Progressing Training Loads to Minimize Injury Risk and Enhance Performance. 50(10), 570–573. https://doi.org/10.2519/jospt.2020.9256

Gabbett, T. J. (2016). The training—injury prevention paradox: should athletes be training smarterandharder? 50(5), 273–280. https://doi.org/10.1136/bjsports-2015-095788

Bowen, L., Gross, A. S, Gimpel, M., Bruce-Low, S., Li, F., (2020). Spikes in acute:chronic workload ratio (ACWR) associated with a 5–7 times greater injury rate in English Premier League football players: a comprehensive 3-year study. 54, 731-738. https://doi:10.1136/bjsports-2018-099422

Boullosa, D., Esteve-Lanao, J., Casado, A., Leonardo Alexandre Peyré-Tartaruga, Gomes, R., & Juan José Salinero. (2020). Factors Affecting Training and Physical Performance in Recreational Endurance Runners. 8(3), 35–35. https://doi.org/10.3390/sports8030035

Saw, A. E., Main, L. C., & Gastin, P. B. (2015). Monitoring the athlete training response: subjective self-reported measures trump commonly used objective measures: a systematic review. 50(5), 281–291. https://doi.org/10.1136/bjsports-2015-094758

Moving Beyond Weekly “Distance”: Optimizing Quantification of Training Load in Runners | Journal of Orthopaedic & Sports Physical Therapy. (2020). Retrieved June 18, 2023, from Journal of Orthopaedic & Sports Physical Therapy website: https://www.jospt.org/doi/10.2519/jospt.2020.9533

Hollander, K., Baumann, A., Zech, A., & Verhagen, E. (2018). Prospective monitoring of health problems among recreational runners preparing for a half marathon. 4(1), e000308–e000308. https://doi.org/10.1136/bmjsem-2017-000308

Physiological demands of running at 2-hour marathon race pace | Journal of Applied Physiology. (2020). Retrieved June 18, 2023, from Journal of Applied Physiology website: https://journals.physiology.org/doi/full/10.1152/japplphysiol.00647.2020

Mayne, R., Bleakley, C. M., & Matthews, M. A. (2021). Use of monitoring technology and injury incidence among recreational runners: a cross-sectional study. 13(1). https://doi.org/10.1186/s13102-021-00347-4

Smyth, B., Lawlor, A., Berndsen, J., & Feely, C. (2021). Recommendations for marathon runners: on the application of recommender systems and machine learning to support recreational marathon runners. 32(5), 787–838. https://doi.org/10.1007/s11257-021-09299-3

Dudley, C., Johnston, R. D., Jones, B., Till, K., Westbrook, H., & Weakley, J. (2023). Methods of Monitoring Internal and External Loads and Their Relationships with Physical Qualities, Injury, or Illness in Adolescent Athletes: A Systematic Review and Best-Evidence Synthesis. https://doi.org/10.1007/s40279-023-01844-x

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These articles and blogs are not designed to replace medical advice. If you have an injury we strongly recommend seeking qualified health advice. To discuss your injury or performance needs, please enquire online to discuss how we can progress you health, performance and fitness journey.

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