Author: Dr. Andreas Fousekis (Strength & Conditioning Coach)
Football or soccer is a highly competitive sport resulting in the occurrence of several injuries to the players with many of their injuries coming from opponent contact-related origins.
These injury types are difficult to avoid and are therefore categorized as non-preventable. When we discuss more of the preventable injury types (muscular in the majority), one specific or particular way of monitoring methodology comes up within the literature time and time again.
This particular way is known as the Acute Chronic Workload Ratio (ACWR) and is suggested as a way of highlighting potential issues in training load that may arise.
This is due to the fact that it may project the athlete’s training load (workload) over the course of one week (acute workload) in relation to the training load performed across the previous 4 weeks (chronic workload).
Training load within the literature can be divided into 2 key silos: 1) Internal and, 2) External load. Internal training load is evaluated with indicators such as heart rate, subjective perception of fatigue (RPE, s-RPE), scale of perception of muscle pain and quality of sleep as well as biochemical indicators.
External load indicators are highlighted through total distance, high speed running, accelerations – decelerations, plus through the energy expended per training session. However, the investigation of the relationship of the load with the cause of injuries is in the early stages.
Training Load Management Course
ACWR & Planning the Weekly Training Load
The quantification of internal and external loads has been extracted from research defining how the performance of athletes can be calculated as the difference between fitness and fatigue (Bannister et al., 1976). The Acute:Chronic workload (ACWR) is based on this research (with the interest of subsequent research data focused on the possible existence of a relationship between ACWR and injury rather than performance) (Gabbett., 2016).
There are three levels according to Figure 1 below: <0.80 (This ACWR number indicates underload in training and as a result a higher risk of injury), 0.80-1.30 (Ideal workload and as a result lower risk of injury), >1.50 (Danger zone and as a result high risk of injury).
Evaluation of ACWR: 2 or 4 Weeks of Monitoring?
Most of the above studies evaluate the load in the last 4 week period before seeing an increased risk of injury. Recent research (Fousekis A, et al. 2022) provided a specific direction for training methods to prevent non-contact injuries through the individual monitoring of each professional soccer player during the playing season where the following observations were found.
First, the results through the ACWR correlated with overall injury frequency among athletes, and secondly, the ratios that most frequently resulted in non-contact injury were at levels approaching several times or exceeding 1.3.
Thirdly, and additionally from the research study, it was found that of the six parameters (TD, 15–20 km/h, 20–25 km/h, 25–30 km/h, ACC>2.5m/s2, DEC>2.5m/s2) recorded and analyzed in blocks of 2 & 4 weeks, the injured players received a more significant load than in the previous one.
It was also suggested in the research that significant changes were observed primarily through the speed parameter at 25–30 km/h, which negatively affected the soccer players who were injured in the blocks of the previous four (Figure 2) and two (Figure 2 below) weeks, with speeds of 15–20 km/h and accelerations.
Moreover, it was observed that in the two-week block analysis, there was a significant deviation between the soccer players (injured and non-injured) regarding the last microcycle, which, in contrast, was less obvious in the four-week block.
In the comparison of specific weeks (2nd and 4th) before the injury and, more specifically, in the four-week period, the following observations were made:
- Soccer players who were not injured for all parameters cumulatively were at 1.04, and those who were injured were at 1.18, while at two weeks the soccer players who were not injured were at 0.98, and those who were injured were at 1.08.
- Significance was observed at four weeks before the injury for three of the six categories, while at two weeks, all six categories were statistically significant and negatively affected an injury.
- In the analysis of both comparative weeks, there was a large discrepancy in the Distance Speed Range category (>25,199 km/h), with 1.58 for the four weeks and 1.47 for the two weeks for the non-contact-injured soccer players.
ACWR Conclusion
Although ACWR can be related to a subsequent occurrence of injury within a football or soccer cohort, the threshold of an ACWR can vary. This variance appears to be mainly influenced by the load assessment of the last two weeks training period than when compared to the four weeks before the injury occurance.
Training load management is one of the hottest debated topics in the game at this moment of time, and coaches or managers who rotate their squad for fitness vs. freshness benefits are in no doubt this is the way to succeed.
Taking individual players fitness, injury history, age & physiology into consideration is key when managing the game & training loads.
What’s Next?
The demand for training load management experts & coaching specialists in football is growing year upon year.
What now? What’s the next step? How do I specialise in this area? Which area of sport science do I want to dive deeper within?
This is certainly an interesting question as progressing from completing a sport science degree to then working in professional football & trying to understanding all the key components, and soft skills that come with jobs in football or careers within sport.
The bespoke courses developed by ISSPF Elite Faculty members are a way of further exposing sport science students, individuals working within the game, coaches, physiotherapists, doctors, sport therapists & other football science enthusiasts with a thirst to develop further in this area.
The link below will take you to the hugely popular & expertly designed ISSPF endorsed & accredited Training Load Management online sports science course, where you will be exposed to football science & specific soccer coaching-led research, practical examples and training load monitoring methods used by leading practitioners within varying levels team sport development.
Join Our Soccer Performance Course
The demand for sports science, physiotherapists, and performance & coaching specialists in football & team sports is growing year upon year.
Thousands of students are leaving university with a sports science degree, physio or therapy-related qualification, however many of them asking the key question – What now?
- How do I get a job in football?
- What’s the next step?
- Which area of sport or football science & medicine do I want to specialise in?
This is certainly an interesting question as progressing from completing a sporting, medical or therapy-related degree to then working in professional football & trying to understanding all the key components, and soft skills that come with jobs in football or careers within sport is complex.
As a result, the bespoke courses developed by ISSPF Elite Medical & Football Science Faculty members are a way of further exposing learners, parents, professional coaches, students, or other individuals interested in football science with a thirst to develop & upskill further.
The link below will take you to the hugely popular & expertly designed ISSPF endorsed & University & Football Association accredited Soccer Science & Performance online sport science course, where you will be exposed to sports medicine & football science with a coaching science led research overview, and practical examples used by the game’s leading practitioners.
Training Load Management Course
How This Course Will Improve You
- Highlights the reasons we should monitor and assess training load in soccer.
- Highlights the practical application of modern training load monitoring & assessment tools.
- Provides an understanding of the need to monitor players training load & minimize training ‘spikes’.
- Helps you to understand the balance between soccer-related fitness, freshness & fatigue.
- Assists in preparing players for the physical, technical & tactical demands in a safe, progressive manner.
- May help us to reduce the risk for non-contact muscle injuries, through a better understanding of planning & preparation.
Who Is This Course For?
- Individuals tasked with the responsibility for the training & coaching aspects of athletes or team sports.
- Individuals with an interest in developing their knowledge in the training & development of individual athletes or team sports.
Course Information
Average Workload: 20 hours total (pre-lecture reading + online content + questions + assignment).
Delivery Method: Online-based.
Language Delivered: English.
What Does This Course Cover?
Training Load Management Course:
Module 1: Soccer player testing & monitoring: Real evidence
Lecturer: Prof. Darren Paul (England)
Module 2: Injury reduction strategies in professional soccer
Lecturer: Dr. Patrick Orme (Bristol City FC)
Module 3: Considerations & Applications of Training Load Monitoring in Elite Soccer Players
Lecturer: Dr. Vasilis Kalapthorakos (Panathinikos, Greece)
Module 4: Soccer specific monitoring: Weekly microcycle, planning and performance
Lecturer: Dr. Dawid Golinski (Slask Wrowclaw, Poland)
Module 5: External load monitoring in professional soccer: Understanding GPS tracking
Lecturer: Dr. Xinji Xi (Catapult, China)
Module 6: Testing and monitoring in soccer: training & games
Lecturer: Dr. Berni Guerro (CF Malaga, Spain)
Topic: Performance Analysis
Module 7: Soccer specific monitoring: Subjective effort assessment
Lecturer: Dr. Dawid Golinski (Slask Wroclaw, Poland)
Module 8: Training Load Management: The appliance of science
Lecturer: Dr. Adam Owen (England FA, Lech Poznan)
Training Load Management Course
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