ABC of Football Medicine® Lesson 8: Athletic Development role in muscle injury prevention – Part 3

Be sure to read  Part 1 or Part 2 of this chapter before going through with this piece.

If you already did, enjoy!

 

Having understood the means and aims of athletic development and knowing how to assess these, the implementation requires that these training sessions be combined with team sport-specific training. For that matter, it is important to understand the key pillars of periodization and how these affect both the strategy to develop capacities as well as the outcomes expected.

Periodization Models of Physical Training in Team Sports

How can physical training fit the weekly microcycle?

Taking into account the competitive schedule of collective sports, it is impossible to consider a traditional periodization model or, in other words, a linear model. This model is characterized by the development of the physical qualities in a linear and progressive way, considering a low intensity/high volume start and progressively higher intensities and lower volumes throughout training cycles. It is a model that is adequate for modalities in which the aim is to perform on one specific event, for which a well defined preparation period exists.

In collective sports, such as football, the performance goal is aimed to be achieved at the start of the season and be maintained (or even optimized) through the entire season. For this reason, a linear methodology isn’t sufficient to maintain the needs of the game. A football athlete generally has 6 to 8 weeks of pre-season where the focus is on the physical characteristics but which is followed by a season of up to 35 weeks, with one or more weekly competitive moments. Besides these constraints, others exist that compromise the traditional model implementation, such as: 1) multiple aims in each training session, that is, the necessity of focusing on different physical qualities; 2) Physical stress induced by the competitive moments/matches; 3) time shortage due to the necessity imposed by technical/tactical training (Gamble 2006).

Responding to this need, the implementation of a non-traditional strategy (Undulatory Model) tends to be more adequate for these sports. This model is based on a variation in the intensity and volume in between training sessions, allowing for the development of several goals throughout these training cycles. (Gamble 2006, Turner 2014). However, linear strategies still have their place, namely during the offseason and preseason, when the goal becomes focused on developing and optimizing physical characteristics with a lesser focus on competition. This combination, adapting the periodization model to the specific competitive moment, allows for the potentiation of the training outcomes. (Gamble 2006, Turner 2014).

With this in mind, we can consider 3 different specific phases for the athletic development of collective sports athletes, namely in football: 1) Preseason period; 2) Competitive period and 3) Offseason Period.

Planning for the Strength and Power Training

From a strength and power development point of view, there are several training models that can be used as guides. In order to build the training schedule, factors such as repetition scheme, prescribed load, rest periods, execution velocity, contraction type along with many others should be considered.

In a general approach, one way of defining the goals of the session and planning the strength training is taking into account the load and rep scheme. This model has some limitations, lacking feedback of the athlete’s performance and ignoring the adverse consequences that may show up when fulfilling the a priori prescribed training scheme. Another way of planning the training session that includes some intra-training monitoring is velocity based training, which focuses the amount of repetitions on the velocity at which they are performed. This method allows for a more efficient and precise training, performing the necessary amount of repetitions and the monitoring of the real work being fulfilled; however, it is also limited by the equipment needs, a reality which not all clubs have. Since the goal of the project is to provide information applicable to all realities, we will not focus on the velocity based methodology. 

The training prescription taking into account the load can be based on an estimation of the One-Repetition Maximum (1RM), from which we can create an interval of training intensities that are adequate for the development of a specific characteristic/manifestation of strength. A 1RM is, by definition, the maximum load that an athlete can mobilize in a certain exercise (not being able to complete a second repetition). In the image below we can identify that in order to train maximal strength and power, we utilize higher loads (around 1 to 6RM), while the aim of hypertrophy is achieved with submaximal intensities of around 6 to 15 RM. It should be understood, logically, that we are talking about a continuum from which unique adaptations cannot be clearly isolated.

Figure 1: Continuum repetition and associated training goals. Source: Essentials of strength training and Conditioning. Third Edition. NSCA. Baechle, T. Earle, R.

The total amount of repetitions of the training session can also be defined according to the different goals to be reached where we can differentiate, for example, a higher volume when focusing on adaptations that mainly target the muscle (both at a structural level, such as hypertrophy, or at a metabolic level such as muscle endurance) or lower volumes that aim to optimize maximum strength and power, promoting neural adaptations.

Figure 2: Resistance Training frequency based on the sport athlete (for a trained athlete). Source: Essentials of strength training and Conditioning. Third Edition. NSCA. Baechle, T. Earle, R.

Both of these methods present themselves with different limitations, especially regarding the development of muscular power, where the evidence points to a set of training options broader than the ones presented in these last two images. Given the relationship between power and the specific actions of football, this will be addressed further in this chapter in order to maximize the planning phase and guaranteeing the optimization of this quality.

As we’ve previously seen, the development of muscle power is directly related to maximum strength; this means that the maximum strength should be assessed when aiming for power. As a reference value, the basal strength achieved in a Half Squat should be 2,0 x Body Weight (BW); meaning that reaching this value should be a priority. Regarding the training itself, we know that the development of power should take into account the several aspects of strength manifestation. This way, it is important to understand and apply the strength-velocity continuum, trying to cover all points of the curve and optimize power at all levels. For this, one way of intuitively differentiating the exercises is to characterize them into strength/velocity, dividing them into regions seen in the figure below with the following description:

  • Max Strength – high intensities (in other words, high values of strength but low velocities) – for example, main lifts like back squat, deadlift (above 90% of 1RM)
  • Strength-Speed  – an intermediate group between peak power output and maximum strength – for example, exercise derivations from weightlifting (80 to 90% of 1RM).
  • Peak Power – zone of optimal power, combining optimal force and velocity in the power production (30 to 80% of 1RM) –  ballistic/explosive exercises, as a weighted squat jump, for example.
  • Speed-Strength – a zone that favours velocity in prejudice of strength – plyometric exercises with slow stretch shortening cycles (SSC), light loaded jump squats and drop & catch derivatives (30 to 60% of 1RM)
  • Maximal Velocity – the maximum velocity that the athlete can produce during any exercise – plyometric with fast SSC such as hops, bounds, sprints (below 30% of 1RM)
Figure 3: Force-velocity curve. Source: Science for Sport

In this manner, the power development training plan should include exercises that aim at different regions of the curve. Besides this, it is crucial that the athletes develop and maintain high levels of maximal strength, requiring that a focus on this characteristic is kept throughout the entire season.

In the following table, we present some guidelines regarding strength and power development.

In order to fit this training typology in a weekly schedule, the ideal scenario would be fitting at least 2 week sessions, one focused on Strength and Hypertrophy (the latter if the need is identified) and the other focused on Power, aiming for neural adaptations.

The beginning of the week should be dedicated to higher volume sessions, where the focus of hypertrophy/maximum strength is developed, since the volume and intensity needed are associated with higher levels of muscle damage and may imply a longer peripheral fatigue.

The power session can be implemented closer to match day, not having a negative impact on performance when occurring up to 72 hours before the game. This session is characterized by low training volumes, associated with a high to moderate intensity; the combination of exercises in the pre-match session may include focus on several regions of the F-V curve but preference should be given to the velocity end of the curve

Planning for Energy Systems Development

Taking into account the existing and most usually utilized methodology in football training, we can infer that the development of the energy system capacities is, from the characteristics described in this chapter, the best developed and already covered. One common way in which we see this development being aimed (while simultaneously developing the technical/tactical aspects) is in small-sided games. This method is commonly used in football and works as a strong stimulus towards the energy system development but has some limitations, namely, the exposure towards high intensity sprints.

Besides the stimulus during training, the stimulus during the match is also a stimulus for this development, taking into account the duration and intensity imposed. This way, complementary training should be used to fulfill the tactical training gaps or target a specific athlete and therefore fulfill the individual and collective needs.

In order to target these goals, the HIIT (High-Intensity Interval Training) training mode  is one of the models most commonly used to fulfill the identified energy system’s needs, mainly due to its practical use and easy implementation. This consists in repetitive effort of high intensity (above the lactate threshold), followed by rest periods (either complete rest of low intensity exercise). Significant improvements have been demonstrated by this methodology, both in aerobic and anaerobic capacities. Besides the physiological benefits, there are also practical benefits: it’s easy to implement.

HIIT can take different properties, from which we can point out: long intervals (long HIIT), short intervals (short HIIT), Sprint Interval Training (SIT), Repeated Sprint Training (RST) and game-based (GB-HIIT, from which the SSGs are examples).

On a short note, and since it is not the purpose of this chapter to go deeper into the characteristics of this specific strategy, we can allocate each of these typologies to different physiological adaptations. This can be seen in figure 4 below.

Long intervals and Short intervals tend to focus on central adaptations but also have an impact on the periphery: they are, therefore, methodologies that focus on capacity and aerobic power. SIT and RST are methodologies that focus mainly on the peripheric adaptations and aim towards anaerobic metabolism adaptation and the capacity of sustaining repeated high intensity stimulus. The prescription of high intensity training may be based on Maximal Aerobic Speed (MAS) but also on Anaerobic Speed Reserve (ASR), as described previously. Since the ASR can take such an important role as an anaerobic capacity marker and given the possible disparity  among players, it is important to consider this factor when planning for intensities above MAS, which require higher demands on the anaerobic system. This can be seen in figure 5.

Figure 4  – HIIT typologies and the associated adaptations. Source: “HIIT” – Buchheit, M.; Larsen, P. 

Figura 5 – Prescribing training intensity, taking into account the MAS and the ASR. Source:  “HIIT” – Buchheit, M.; Larsen, P.

The weekly plan of this type of training will depend largely on the training methodology practiced by the technical team. However, the goal is the same: complement the training session with a similar energy system training in the physical session. This way, during a “regular” week, the highest volumes and highest intensities (from a mechanical point of view), should be saved for the first sessions of the week. This work should be reduced in volume and intensity (again, in mechanical terms) and replaced by higher intensity strategies that impose lower peripheral fatigue indexes. One such example of  the application of this way of reasoning is seen below:

 

Figura 6 – Weekly HIIT planing. Source: “HIIT” – Buchheit, M.; Larsen, P. 

With this said, the role of athletic development in injury prevention is nothing but the application of basic training  principles, structuring a plan that takes into account the athlete’s needs and what develops him/her as a whole, enhancing their capacities and making them the most capable, resilient and robust as possible to face the inherent demands of the sport.

It should be easy to understand and agree that an X or Y plan, which is based only on one exercise or on a generic group of exercises is not an optimal way to develop the athletic component as a whole, since it is not specific and will not be able to respond to the imposed needs. The goal of this chapter is to guide the reader through the thought process, by first understanding the needs and the theory basis associated with each capacity, understanding how to assess and identify the points to be improved and finally, to help in the decision making, culminating into a plan that is directed to the needs of each athlete.

We’d like to end this section with one last disclaimer: the athletic development, as a stand-alone, will not prevent injuries, as it presents itself only as a piece of the puzzle. It will act as a moderator in this process, transforming the players into athletes and the athletes into the fittest and strongest version of themselves: and that will minimize the risk of injury.

Having completed the 3 initial requirements for athletic development, we now present a case example of how all of the theory described above applies to one “real player”.

 

Case Example

Practical Application of the athletic development training implementation

Our athlete is a young male player, 24 years old and plays as a Right Back; he’s an explosive player performing in a team that has a strong offensive character that requires his constant participation in the offensive movements of the team. He has an injury history, with a torn left hamstring (2b Biceps Femoris muscle tear occurring last season).

Needs Analysis: Taking into account the context that won’t allow for an extensive test sequence and given that the goal is to create an efficient testing sequence from a time perspective while still retrieving enough information that can be used to assess the basic physical qualities to be developed into a football player, it is relevant to test the following dimensions:

  • Strength and Power: MaxStrength and Power assessment of the inferior limbs should be a priority and transverse throughout the team. Besides the general tests, a specific assessment can and should be included given the injury history: this means testing the hip extensors and knee flexors (the reason why testing the endurance strength in order to assess the asymmetries between limbs was included)
  • Energy Systems: Given the specificity of the playing position, it is important to assess the aerobic capacity estimated through MAS, as well as the anaerobic capacity, extrapolated by the aforementioned formula ASR = Maximum Sprinting Speed – MAS.

Initial assessment:

Considering the initial assessment we can see that:

  • Max Strength: 1,89 x BW  is below the reference value (2,0x BW)
  • Power Values:
    • Squat Jump (SJ) and Counter Movement Jump (CMJ) both have acceptable values (above 30 and 35 respectively), however the goal is to optimize these values (35cm of SJ and 40cm of CMJ as reference values).
    • Single Leg (SL) Hop with an 11% asymmetry – should be taken into account, however it is not a significant difference due to the specificity of the sport (preference for the limb may be responsible for this imbalance).
  • Specific Injury Assessment: Asymmetry of 22% on the SL Hamstring Bridge should be noted, with the training goal aiming to mitigate this difference, becoming an injury protective factor (minimizing the asymmetry to < 10%)
  • ESD: MAS (4.6 m/s) below the reference levels (4.8 m/s). The ASR is within acceptable values, considering the work group/team colleagues from the same position.

The Training Plan has the following goals: 

  1. Optimize Max Strength Levels;
  2. Mitigate the asymmetry found in the specific injury assessment;
  3. Optimize aerobic capacity

Guides for the planning:

General Fitness Preparedness (GFP) – 3 to 4 weeks:

  • Strength and Power: Hypertrophy Methods – intensities of 60 to 80% associated with high training volumes in an initial period, divided between 3 days. Increase in intensity and decrease in volume from week to week. Fundamental movement patterns, bilateral and unilateral exercises, with focus on movement range and time under tension (duration of the contraction).
  • Energy System Development: Higher volume of complementary energy systems work: two blocks of long interval  and one block of short interval work. The goal is to expose the maximum amount of time to VO2max levels, mainly promoting central adaptations and therefore, optimizing aerobic capacity.

Specific Fitness Preparedness (SFP) – 3 to 4 weeks:

  • Strength and Power: A decrease in training volume and an increase in intensity, with now only two training blocks: 1) full body – muscular adaptations- hypertrophy methods; 2) Lower body – peripheral adaptations – methods dedicated to Max Strength and power development. A shift in training goals occurs, with more specific exercises, especially in day 2: specific ranges, focus is on speed execution in the Lower Body.
  • Energy System Development: Decrease in work volume and increase in the intensities; we aim to decrease complementary training, with only 2 sessions: 1) one block of long interval and 2) one block of short interval. The goal is to optimize central adaptations but also promote peripheral adaptations: aerobic and anaerobic capacity.

Reassessment after preseason period

Upon reassessment: 

  • Max Strength: reached the reference value, now 2,06xBW.
  • Power Values:
    • SJ and CMJ between the proposed values but still with a progress margin (38 and 42cm respectively). The goal now could be to aim towards passing 40 and 45cm, respectively.
  • Specific Injury Assessment: Asymmetry of 6% in the SL Hamstring Bridge test (goal was below 10%).
  • ESD: MAS reached reference values (4,83 m/s). The ASR is also within acceptable values, regarding team colleagues.

Goals of the Training Plan:

  1. Maintain Max Strength levels;
  2. Optimize power values throughout the season;
  3. Maintain strength stimulus at the hamstring level, given the clinical history;
  4. Maintain aerobic and anaerobic fitness.

Guides for the in-season plan:

Strength and Power: Non-linear periodization, where the variation of volume and intensity is adapted to the microcycles according to needs. The plan should be readjusted every 4 to 6 weeks in order to optimize the training effects, with one possible weekly microcycle  being presented below:

  1. One full body block: characterised by a bigger work volume and with focus on allowing for a muscular stimulus.
  2. One lower body block: characterised by a low work volume dedicated to the development of power.

 

Authors: André Mendes e Lucas Brink Carvalho

Thank you for joining us for this 3 part trip.
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APPENDIX:

The assessment examples mentioned at the section two include – MaxStrength (half squat e trapbar deadlift), Power (SL Hop, Broad Jump, SJ, CMJ) and a injury specific test (SL hamstrings bridge).

MaxStrength

Power

Injury Specific Test

 

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