You are a couple of weeks out from the players returning from their off-season break. The performance team are meeting to iron out the preseason plan and determine what the first couple of weeks of training will look like for the entire playing squad and specifically for various members of the squad. The performance team are crossing their fingers and hoping that the players were diligent and compliant with their offseason training programmes.
The reality is, even at the very top end, only a small portion of the squad will have accomplished what you set out for them to achieve over the off-season. Despite this, even if they did execute the off-season plan, to a tee, it is unlikely the loads they experienced will match or surpass what they will need to experience throughout preseason and into the competitive season.
There are the usual nerves around certain players/”frequent offenders” and so the performance team agrees to start week 1 preseason with loading that caters for the lowest common denominator. The “loading clock” then starts ticking down from session 1 to the first preseason game and the pressure is on. If you push them too hard and too soon there is the risk of breaking them, if you don’t push them hard enough, game loads and back to back games will eventually break them, if you don’t start “meaningful work” early enough you’ll run out of time or you’ll run the risk of not allowing sufficient recovery/regeneration within your preseason and again there is the chance they will break.
Early preseason becomes critical to determine the physical state by which players return. It presents an ideal opportunity to assess the physical status of the playing group as a collective and importantly for the individual. Depending on the sport and the length of the off-season it may also be a period of time where fatigue is at its lowest point and niggles carried through the previous season are somewhat settled. Collecting assessment data to determine baselines and to determine current status in which to load from, is essential during this part of the year.
The challenge for most performance teams is time and the “time-tug-of-war” between the sport coaches demands and the performance teams needs. Some teams are fortunate enough to be able to negotiate and establish clear blocks of time early in pre-season where they conduct their screening and assessments. Others don’t have the buy-in, collaboration and support and therefore squeeze whatever they can in, whenever they can. Often in these environments the data sets are incomplete, unreliable, messy and not really useful at all. Pre-season assessments and screening in these environments become a “tick box exercise” and sadly everyone knows it and feels it – including the players.
High Performance Managers, who establish strong and trusting relationships and have the ability to influence Head Coaches, are critical in balancing the needs of both parties in this scenario. Strategically imbedding pre-season assessments and screening within the training week has often been a fantastic middle ground for most teams. The planning, the sell, the execution and the follow up of this to players and coaches can make or break the success and effectiveness of pre-season assessments and screening moving forward.
In pre-season planning all facets of load are important to consider from strength training intensity, plyometric volume, and eccentric exposure to running volume, change of direction count and the magnitude of collisions, for example. One of the most important load factors to consider is the intensity, volume and density of “very high speed” and maximal speed running (herein referred to as “high speed running” [HSR]). Any combination of too fast, too much, too often, too soon have had many a performance coach lose sleep at night.
During HSR lower limb muscle groups produce very high forces at very high rates. In the swing phase the hip flexors and the hamstrings can produce muscle forces up to ~10 x BW. Muscle force production in the stance phase can be up to ~10 x BW for the plantar flexors and ~5 x BW by the quadriceps (Dorn et al. 2012). Ground reaction forces experienced at HSR running can be up to 4 x BW and occur in less than 100 ms (Weyand et al., 2010).
HSR, particular in a training format, is a potent stimulus to the neuromuscular system. Significant central and peripheral fatigue have been observed after HSR sessions and even with relatively low volumes, several days are required to fully recover (Johnstone et al. 2015; Thomas et al. 2018). Due to these, and several other, biomechanical and physiological demands, HSR is a significant risk factor in soft tissue injuries (Gabbet et al. 2012; Duhig et al. 2016; Chavarro-Nieto et al. 2023).
Therefore, the careful planning of HSR exposure in the pre-season is critical. Where you can start and where you can go with your players often comes down to what HSR exposures (intensity, volume, density, frequency and type) were achieved during the off-season period. Despite this the deload experienced in the off season often means the regression or degredation of certain physical qualities. With the muscular forces and ground reaction forces seen in HSR the notion to be “strong enough to run fast” needs to be seriously considered along with HSR exposure.
Early pre-season assessments of both maximal and rapid force of the lower limbs are essential to understand the requisite force generating capacities of key muscle groups involved in HSR. As addressed earlier, the early preseason period provides an opportunity to establish baselines but also to compare to in season/previous season values and assess the magnitude or otherwise of degradation. In my opinion “earning the right to run fast” is a combination of graded specific HSR exposure and developing or retaining the underpinning force generating qualities to be able to handle the forces experienced in HSR.
The isometric mid-thigh pull (IMTP) presents a proven, reliable, effective and long-standing assessment of maximal force and rapid force generating qualities. The IMTP and its close cousin the isometric squat assessment are excellent assessments that practitioners can administer safely in early pre-season to establish force generating qualities of the lower limb. In comparison to the risk of maximal strength testing returning players both assessments are certainly the preference.
However, despite being effective general force assessments they lack the specificity to identify force generating capabilities of specific muscle groups at the specific muscle lengths used in HSR. Assessing positions and postures resembling HSR positions and postures, whilst more effectively isolating key muscle groups around the ankle, knee and hip joints are becoming more popular in high performance settings. In doing so we can collect more information to make more informed decisions around whether and when players are in fact “strong enough to run fast”.
One such force assessment battery is the Run Specific Isometric Assessment Battery involving the Ankle Iso-Push, Knee Iso-Push and the Hip Iso-Push. The assessments are similar to the joint positions found in mid-stance of the HSR stride. Importantly the Run Specific Isometric assessments are multi-joint assessments, despite each individual assessments name, they do not strictly isolate the force generating capabilities of a single joint. The Run Specific Isometric assessments are designed to bias a joint and this is where we infer the force generating capabilities of the muscles surrounding the target joint. The Run Specific Isometrics assessments are all performed unilaterally to further elucidate any inter-limb discrepancies and asymmetries.
Both the Knee and the Ankle Iso-Push are performed in an upright, standing position. The Vald Performance ForceDecks Dual Force Plate system are used in an isometric rig, however these tests have also been performed using overloaded barbels resting on the pins or barbells pushed under the pins of a racking system. The Knee and Ankle Iso-Push are performed with the bar on the upper trapezius muscles, as in a high bar squat set up. In the Knee Iso-Push the mid-foot of the tested leg is placed directly under the bar and the knee and hip angles are between 135-145∞ and 160-170∞ respectively. In the Ankle Iso-Push the ball of the foot of the tested leg is placed under the bar to facilitate a slight forward lean. In this assessment the knee and hip are fully extended, and the ankle positioned between neutral to 10∞ of plantar flexion.
In the Hip iso-Push the athlete lays supine on the floor with the inferior portion of their shoulder blades resting on a comfortable 15cm box. The heel of the testing foot is placed on the force plates and an immoveable bar is positioned at their hip crease. The knee and hip angles in the Hip Iso-Push resemble that of the Knee Iso-Push (135-145∞ and 160-170∞ respectively). Importantly, we measure these angles when the athlete lifts their hip from the floor and presses them into the bar.
A general warm up is conducted before the assessments and a specific warm up is performed for each assessment immediately before the test. The specific warm up consists of 3 x 3 s efforts at 70, 80 and 90% effort with 10 s recovery between each. The athlete then rests for 60 s before performing either a rapid force assessment or a maximal force assessment. Rapid force assessments consist of 5 x 1s efforts interspersed with 10 s recovery. Maximal force assessments consist of 2 x 3 s efforts with a 2 s “build up”. Each effort is followed by a 60 s rest. A third trial is performed if the second trial is >3% of the first trial. Generally relative peak force is captured and reported for maximal force trails and force at 100 ms for rapid force trials.
Although normative data are used to guide and compare male and female team sport athletes, in the context of being “strong enough to run fast” it is also important to assess each athlete against their previous seasons results. “Good” results for female team sport athletes for a Hip Iso-Push would be ~1.95-2.15 x system weight (the system weight is the amount of body weight supported at the heel in the tested supine bridge type position [~25% of body weight], Knee Iso-Push ~3.85-4.2 x BW and Ankle Iso-Push ~2.75-2.9 x BW.
For male team sport athletes, a good Hip Iso-Push would be 2.2-2.5 x system weight, Knee Iso-Push 4.2-4.4 x BW and Ankle Iso-Push 3.1-3.3 x BW. For comparison, elite male track athletes can attain Hip Iso-Push scores of 3+ x system weight, Knee Iso-Push scores of 5.5+ x BW and Ankle Iso-Push scores of 4.0+ x BW. It is very rare for team sport athletes to hit these values but what this does show is that there is plenty of room to improve in strengthening the key muscles for HSR.
Over an off-season period of 4-8 weeks it is not uncommon for a team sport athlete to drop between 0.25-0.5 x BW maximal force in the Knee and Ankle Iso-Push for example. Regaining this strength is paramount and should be prioritised along with the introduction of progressively increasing HSR exposure and plyometric progressions. Just as important is attaining previous levels of force at 100 ms. With brief ground contact times during HSR it is arguably more important to either produce high rates of force or a greater proportion of maximal force in that brief time period. Very explosive athletes can produce up to 80% of their maximal force in 100 ms and less explosive athletes <60%. Again, what is most important in the returning athlete is to regain their previous season values to “earn the right” to run fast.
Performance teams can use the Run Specific Isometric Assessments imbedded within the preseason week 1 to ascertain the HSR starting point and progression rates of each of their players. In the simplest terms, if a fit returning player has had good HSR exposure through the off season and returns with maximal force and rapid force scores within their normal range, a more regular or even aggressive HSR approach might be warranted. If a player returns having achieved the planned high speed running exposures over the off season, attains within their range of their previous maximal force values but fails to attain their previous force at 100 ms then as more cautious HSR loading scheme might be planned. Clearly if a player has not had HSR off season exposures and fails to attain within range maximal force or rapid force levels then a conservative loading approach is likely to be planned.
In summary, the early preseason is a critical time to establish normative assessment and screening data for your players. The information provided can be used to identify the magnitude, rate and extent by which you can load your players leading to the start of competition. Earning the right to run fast is determined through HSR exposures and also through the current force generating capabilities of the key muscles used in HSR. The Run Specific Isometric Assessment Battery provides a good under the hood look at whether your players are returning strong enough to run fast.
References
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Weyand PG, Sandell RF, Prime DN, Bundle MW. The biological limits to running speed are imposed from the ground up. J Appl Physiol (1985). 2010 Apr;108(4):950-61. doi: 10.1152/japplphysiol.00947.2009. Epub 2010 Jan 21. PMID: 20093666.
Thomas K, Brownstein CG, Dent J, Parker P, Goodall S, Howatson G. Neuromuscular Fatigue and Recovery after Heavy Resistance, Jump, and Sprint Training. Med Sci Sports Exerc. 2018 Dec;50(12):2526-2535. doi: 10.1249/MSS.0000000000001733. PMID: 30067591.
Johnston M, Cook CJ, Crewther BT, Drake D, Kilduff LP. Neuromuscular, physiological and endocrine responses to a maximal speed training session in elite games players. Eur J Sport Sci. 2015;15(6):550-6. doi: 10.1080/17461391.2015.1010107. Epub 2015 Feb 12. PMID: 25674673.
Gabbett, Tim J; Ullah, Shahid. Relationship Between Running Loads and Soft-Tissue Injury in Elite Team Sport Athletes. Journal of Strength and Conditioning Research 26(4): p 953-960, April 2012. | DOI: 10.1519/JSC.0b013e3182302023
Duhig S, Shield AJ, Opar D, et al. Effect of high-speed running on hamstring strain injury risk. British Journal of Sports Medicine 2016; 50: 1536-1540.
Christian Chavarro-Nieto, Martyn Beaven, Nicholas Gill & Kim Hébert-Losier (2023) Hamstrings injury incidence, risk factors, and prevention in Rugby Union players: a systematic review, The Physician and Sportsmedicine, 51:1, 1-19, DOI: 10.1080/00913847.2021.1992601
