Load Management

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Introduction[edit | edit source]

Over the last few decades sport has become a competitive, professionalised industry.[1] Athletes have to deal with fuller competition calendars and face increasingly higher pressure to stay competitive.[2] Consequently, athletes of all levels as well as their coaching staff are relentlessly aiming to improve performance[2]. Although there are a multitude of factors that can contribute, the main factor athletes focus on is usually their training methods.[2] Training and competition load causes a series of homeostatic responses and adaptations in the human body.[3][4][5] The key factor in training theory is to implement this process of biological adaptation to improve fitness and eventually improve performance.[5] Furthermore, a principal goal in rehabilitation is improving capacity to manage load and this has been discussed in the literature in relation to tendinopathy[6] and cartilage repair[7].  There is also good evidence for load management to prevent illness and over-training in athletes.[2]

Poorly managed training loads in conjunction with the full competition calendar may influence the health of athletes.[8][9][10] The balance between external load and tissue capacity plays a significant role in injury[11] and although there are various intrinsic and extrinsic factors[12] involved in injuries, there is evidence to suggest that load management is a key risk factor for injury.[13]

The relationship between load and health is considered as a well-being continuum, with load and recovery as mutual counter agents.[2] Also, during rehabilitation processes, initially we might consider reducing load to allow pain to settle and allow gentle specific exercise prescription. Later we will gradually increase load by progressing the exercise prescription appropriate for restoring normal function specific for an individual and their disorder as symptoms allow.

Terminology[edit | edit source]

The IOC Consensus statement on load management[2] defines load as "the sport and non-sport burden (single or multiple physiological, psychological or mechanical stressors) as a stimulus that is applied to a human biological system (including subcellular elements, a single cell, tissues, one or multiple organ systems, or the individual). Load can be applied to the individual human biological system over varying time periods (seconds, minutes, hours to days, weeks, months and years) and with varying magnitude (i.e. duration, frequency and intensity)."[2]

External load refers to any external stimulus applied to the athlete that is measured independently of their internal characteristics.[14] Internal load refers to the physiological and psychological response in an individual following the application of an external load.[14]

Monitoring of load and injury[edit | edit source]

Monitoring athletes is essential in order to define the relationship between load and risk of injury in the management of athletes as well as in research. This includes not only the accurate measurement and monitoring of the external and internal loads on the athlete, but also the performance, emotional well-being, symptoms and injuries of the athlete.[2]

Benefits of scientific monitoring[edit | edit source]

  • explain changes in performance
  • increased understanding of training responses
  • identification of fatigue and accompanying needs for recovery
  • informing the planning and modification of training programmes as well as competition calendars
  • ensuring therapeutic levels of load to minimise the risk of non-functional over-reaching (fatigue lasting weeks to months), injury and illness[2][14]

Monitoring external and internal loads[edit | edit source]

Different measures of load are available, but the evidence for their validity as markers of adaptation and maladaptation is limited.[2] There is no single marker of an athlete's response to load that consistently predicts maladaptation or injury.[15][16]

Examples of measurement tools to monitor external loads[edit | edit source]

  • Training or competition time[17]
  • Training or competition frequency[18]
  • Type of training or competition[19]
  • Time-motion analysis[20]
  • Power output, speed, acceleration[21]
  • Neuromuscular function (eg. jump test, isokinetic dynamometry and plyometric push-up)[22]
  • Movement repetition counts (eg, jumps, throws, pitches, serves, bowls)[23]
  • Distance (eg kilometres run, swam or cycle)[24]
  • Acute:chronic load ratio[25]

Examples of measurement tools to monitor internal loads[edit | edit source]

  • Perception of effort (eg, rate of perceived exertion-RPE)[26]
  • Session rating of perceived effort (session duration (min) x RPE)[26]
  • Psychological inventories (eg, profile of mood states (POMS)[27]; Recovery stress questionnaire for athletes (REST-Q- Sport)[28]
  • Sleep (e.g. sleep quality and sleep duration)[29]
  • Biochemical/hormonal/immunological assessments[14]
  • Heart rate (HR)[30]
  • HR to RPE ratio[31]
  • HR recovery (HRR)[32]
  • HR variability (HRV)[33]
  • Blood lactate concentrations[34]
  • Blood lactate to RPE ration[35]

Monitoring external load is key to understanding the work completed, the capabilities of the athlete as well as the athlete's capacity. Internal load monitoring is vital in establishing the appropriate stimulus necessary for ideal biological change.[2] It is evident that individuals will respond differently to any given stimulus and that the load required will differ for each individual. There is no "one size fits all" solution.[2]

Practical guidelines for load management[edit | edit source]

The overall aim of proper load management is to ideally construct training, competition and other load to enhance adaptation and maximise performance whilst also reducing the risk of injury.[2] It therefore, entails the correct prescription of load as well as the correct monitoring and change in external and internal loads.

Prescribing training and competition load[edit | edit source]

  • High loads may have either positive or negative effects on injury risks in athletes. The key factors are the rate of load application and the intrinsic risk profile of the athlete. Athletes respond significantly better to smaller increases and decreases in load, than big variations in loading. Different sports will have different load-injury profiles. Current evidence from sports such as Australian football, cricket and rugby league recommends that athletes should limit weekly increases of their training load to less than 10% or maintain an acute:chronic load ratio within a range of 0.8 - 1.3, in order to maintain in positive adaptation and therefore reduce the injury risk.
    • Acute load is the absolute workload done in 1 week and chronic load is the average acute workload done in 4 weeks. The ratio between acute and chronic shows if the acute workload is greater or less than the total workload of the weeks before it[36]
    • A acute:chronic workload of 0.5 means that the athlete trained/competed half of what was prepared for the 4 weeks prior[37]
    • A ratio of 2.0 means the athlete did twice as much, anything more than 1.5 is seen as a spike in training and could be seen as an injury risk.[37]
  • In football it has been shown that playing two matches (i.e., less than 4 days recovery between matches), compared to one match per week, increases the risk of injury. It is therefore suggested that football teams should contemplate squad rotations to protect individual players from large increases in match loads which may put them at higher risk of injury.
  • There is no "one size fits all" principle. Load should be prescribed or recommended on an individual and flexible basis, as there is a large variation in the time frame of response and adaptation to load.
  • The load management in developing athletes should be monitored closely, as these athletes are at higher risk for injury when introduced to new loads, changes in load or difficult competition calendars.
  • The prescription of training and/or competition loads should be guided by the variation in an athlete's psychological stressors.
  • Adequate recovery sessions should be incorporated after intensive training periods, competitions and travel. Furthermore, care should be given to nutrition, hydration, sleep, rest, active rest, relaxation strategies and emotional support.
  • The health of the athlete is paramount and sports governing bodies should consider this when planning their event calendars. Therefore, it is vital that there should be an increased coordination between single-sport and multisport event organisers, and the development of a comprehensive calendar of all international sports events.

Monitoring loads[edit | edit source]

Scientific monitoring of an athlete's load is essential for ideal load management, athlete adaptation and injury management in sport.[2]

  • Coaches and support staff should invest in scientific methods to monitor the athlete's load and detect meaningful change.
  • Always monitor load individually.
  • Employ a combination of external and internal load measures relevant and specific to each sport.
  • Subjective load measures are useful and coaches and support staff are encouraged to make use of these measures.
  • Monitor load by using a comprehensive approach that takes into account interaction with other intrinsic and extrinsic factors such as history of injury, age and sex.
  • Special care should be given to the monitoring of an athlete's acute and chronic workload, as well as the acute:chronic load ratio of an individual athlete.
  • Frequent monitoring is suggested to enable acute adjustments to training and competition loads.

Monitoring of injury[edit | edit source]

Monitoring an athletes health can lead to early detection of symptoms and signs of injury, it can aid in early diagnosis and guide the appropriate intervention.[2]

  • On-going scientific injury surveillance systems should be employed in all sports
  • Monitoring tools should be sensitive to acute and overuse injuries, as well as early clinical symptoms such as pain and functional limitations
  • Injury monitoring should be on-going, but at least occur for a period of time (at least 4 weeks) after rapid increases in load.

Misconceptions about Training Load[edit | edit source]

Evidence based guidelines to reduce workload related injury are often inadequately implemented. Various reasons for this may be:

  • level of expertise or understanding of training load of the management team (medical team, strength and fitness coaches, skills coaches)
  • the individual beliefs of the management team
  • the individual experiences of the management team

These factors create a gap between the evidence supporting training load and it's role in injury and the actual training programs prescribed to athletes.

Misconception #1: Load explains all injuries[edit | edit source]

The relationship between training load, performance and injury has been researched extensively. Performance can, in part, be explained by training load - higher training load is often associated with better performance.

There is also evidence that inappropriately described training load may cause injury (or an increased risk of injury) and pain. When considering these findings, one might think that "load explains all injuries."

However, there are many influencing factors of performance and injury. Adaptation to training may be influenced by numerous factors such as:

  • biomechanics
  • emotional stressors
  • lifestyle stressors
  • sleep patterns

It is therefor imperative to understand that relationship between training load, performance and injury is complex and multifactorial.

Misconception #2: The "10% rule"[edit | edit source]

Hypothetical relationship between chronic training load and weekly changes in training load. Each block represents a 10% increase in weekly training load. Smaller increases (<10%) in weekly training load are recommended when the chronic training load is either extremely low or extremely high (indicated by red blocks). Larger increases (>10%) in weekly training load are likely to be well tolerated by athletes with moderate to high chronic load and may be necessary to accelerate the rehabilitation process (indicated by green blocks).

A common method to introduce graded increases in training load is by using the 10% rule, where the guideline is that training load increase should not exceed 10% per week. Although it has been shown that rapid increases in training load increases the risk of injury, there is no 10% rule. It is important to understand that risk of injury ≠ rate of injury.

Changes in training load should be interpreted in relation to the chronic training load of the individual athlete. For example, an athlete with a low chronic training load who introduces small weekly increases in training load (≤ 10%), will have a delayed return to full capacity. On the other end, an athlete with a high chronic training load may only be able to tolerate smaller increases in training load.

Smaller increases in training load (≤10%) can be recommended in athletes with either an extremely low chronic training load or in athletes with an extremely high chronic training load. Athletes with moderate to high chronic training loads may be able to tolerate larger increases (≥10%) in weekly training load. These increases may also be needed to accelerate the rehabilitation process.

The 10% rule should rather be seen as a guideline rather than a rule or code.

Misconception #3: Avoid "spikes" and "troughs" at all costs[edit | edit source]

The acute:chronic work rate ratio (ACWR) is determined by the acute training load (size of the current week's training load) in relation to the chronic training load (longer term training load). In various sports it has been shown that rapid increases ("spikes") in training load have been associated with increases in injury risk. An ACWR between 0.8 and 1.3 (meaning that the acute training load is more or less equal to the chronic training load) indicates that the risk of injury is relatively low. But, if the acute training load is much greater than the chronic training load and the ACWR is ≥ 1.5, there is an increased risk of injury. It has been suggested that athletes should therefor keep their ACWR ≤1.5 to minimise the risk of injury. However, the nature of injuries are multifactorial. It is also evident that some athletes sustain injuries even with their ACWR ≤ 1.5 and other athletes can tolerate ACWR ≥ 1.5. This indicates that even if an athlete is at risk of injury, the injury might never happen. "Risk does not equal rate."

There is also the possibility that too little training ("troughs" in work load) may also increase the risk of injury. Overtraining and undertraining may therefor both contribute to the increased risk of injury. Undertraining leaves athletes underprepared for competition demands and generally "troughs" in workload precedes "spikes" in workload. Although these changes in training work load can increase injury risk, it does not mean that practitioners should never rapidly increase training load or unload athletes. Evidence shows that high intensity training blocks do facilitate greater physiological adaptations and athletes who reduce their training load during the taper period have an improvement in performance.

See also[edit | edit source]

Principles of exercise rehabilitation

A great summary on load management is also available at Balancing training load and tissue capacity. by T. Goom, Running physio,2015.

References[edit | edit source]

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