The first Greek site in football training

Applied Sports Scientist

Education

  • 1995-2002: MD, Medical School, University of Ioannina, Greece
  • 2003-2009: PhD,Medical School, University of Ioannina, Greece

Background

  • 2009-present: Applied Sports Scientist Orthopaedic Sports Medicine Center. Research in the areas of Applied Sports Science and Sports Medicine. Monitoring fitness training and fatigue management. Integration of training load, injury risk, fatigue assessment and performance optimization. Planning and programming of the annual training plan.
  • 2009-2014: FC PAS Giannina . Physiological support (laboratory and field performance assessment).

Date of birth

02/09/1976

Kostas Patras

Trainings - Kostas Patras

Laboratory evaluation

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VO2max represented the single most used physiological variable in soccer fitness testing during 1980-2000 (1). A range of has been proposed as a “cut-off” threshold for a successful elite male soccer player (1, 2); however there is considerable variation in VO2max values among professional soccer players from different countries (Table 1).

Study

Sample (n)

Country

Mean±SD

(mL·kg–1·min–1)

Sporis et al, 2009

270

Croatia

60.1±2.3

Ziogas et al, 2010

53

Greece

58.8±3.3

Arnasson et al, 2004

225

Iceland

62.5±4.8

Haugen & Seiler, 2015

598

Norway

63.0±3.0

Table 1. Mean±SD VO2max values in large cohorts of professional soccer players.

It appears that VO2max alone can not discriminate between players of different status in large cohorts of players (4, 6, 7). For example in a pre-season testing of 129 professional soccer players, VO2max could not discriminate playing standard (Div A=58.8±3.3 mL·kg–1·min–1; Div B=56.4±3.7 mL·kg–1·min–1; Div C=57.6±3.2 mL·kg–1·min–1) (4). More recently, it was observed that VO2max could not discriminate among national-team players, 1st and 2nd division players, in a cohort of 1545 players (7). From a training perspective VO2max can increase up to 6% (58.7±4.4 mL·kg–1·min–1 to 61.2±4.1 mL·kg–1·min–1) in high level professional players which requires accumulating 7.3±2.9% of the total training time during an 8 week pre-season period at high-intensities (≥90% HRmax) (8). However further increase during the in-season is not always evident (7, 9). VO2max has a typical error of 2.0-3.4% and a smallest worthwhile change of 1.5%, therefore a likely “true” positive change for a single athlete should be between 3.5-5% (10). This would require a player entering the competitive season with a VO2max of 60 mL·kg–1·min–1 to produce a mid-season value of 62.1-63.0 mL·kg–1·min–1. Despite optimization in high intensity aerobic training (11), striving to produce such increases during the in-season may come at the expense of other important fitness attributes (6).

Key points

  • VO2max alone is not a reliable indicator of playing standard.
  • Definite positive changes can be obtained during the pre-season.
  • Due to the large typical error of the variable, small in-season individual changes will (most likely) be unclear.
  • The inconclusive nature of the in-season changes along with the maximal effort required for the test may increase the likelihood of omitting the test altogether.

REFERENCES

  1. Stolen T, Chamari K, Castagna C, Wisloff U. Physiology of soccer: an update. Sports Med, 2005; 35:501-536.
  2. Reilly T, Bangsbo J, Franks A. Anthropometric and physiological predispositions for elite soccer. J Sports Sci, 2000; 18:669-683.
  3. Sporis G, Jukic I, Ostojic SM, Milanovic, D. Fitness profiling in soccer: physical and physiologic characteristics of elite players. J Strength Cond Res, 2009, 23:1947-1953.
  4. Ziogas GG, Patras KN, Stergiou N, Georgoulis AD. Velocity at lactate threshold and running economy must also be considered along with maximal oxygen uptake when testing elite soccer players during preseason. J Strength Cond Res, 2011; 25:414-419.
  5. Arnason A, Sigurdsson SB, Gudmundsson A, Holme I, Engebretsen L, Bahr R. Physical fitness, injuries, and team performance in soccer. Med Sci Sports Exerc, 2004; 36:278-285.
  6. Haugen T, Seiler S. Physical and physiological testing of soccer players: Why, what and how should we measure? Sportscience, 2015; 19:10-26. Available at www.sportsci.org/2015/TH.htm.
  7. Tonnessen E, Hem E, Leirstein S, Haugen T, Seiler S. Maximal aerobic power characteristics of male professional soccer players, 1989-2012. Int J Sports Physiol Perform, 2013; 8:323-329.
  8. Castagna C, Impellizzeri FM, Chaouachi A, Manzi V. Pre-season variations in aerobic fitness and performance in elite-standard soccer players: A team study. J Strength Cond Res, 2013; 27:2959-2965.
  9. Kalapotharakos VI, Ziogas G, Tokmakidis SP. Seasonal aerobic performance variations in elite soccer players. J Strength Cond Res, 2011; 25:1502-1507.
  10. Hopkins WG. How to interpret changes in an athletic performance test. Sportscience, 2004; 8:1-7. Available at www.sportsci.org/jour/wghtests.htm.
  11. Buchheit M, Laursen PB. High-intensity interval training, solutions to the programming puzzle: Part I: cardiopulmonary emphasis. Sports Med, 2013; 43:313-338.
Kostas Patras
Injury prevention/rehabilitation

The hip rotators are mostly located at the posterior aspect of the hip (Table 1). The hip external rotators specifically are considered important for the execution of the instep and side-foot kicks (1, 2). It has been theorized that excess stress stemming from the execution of repetitive movements may result in muscle tightness (3). Given that instep and side-foot kick are fundamental activities in soccer practice, it may be concluded that these muscle groups may be susceptible to tightness. A less than optimal range of motion may affect quality of force production and application and will be associated with energy leaks (4). In addition poorly conditioned hip rotators may lead to abnormal lumbo-pelvic posture and lumbar spine motion during athletic movements (5).

External rotators

Internal rotators

Psoas

Gluteus medius (anterior fibers)

Illiacus

Gluteus minimus

Sartorius

Adductor magnus (anterior fibers)

Gluteus maximus

Adductor longus

Gluteus medius (posterior fibers)

Adductor brevis

Biceps femoris (long head)

TFL

Adductor magnus (posterior fibers)

ST/SM

Piriformis

Table 1. External and internal rotators of the hip joint.

Research indicates that the hips are affected in soccer players since hip-rotation ROM decreases over the years in soccer players (6) and both youth and senior footballers have significantly less internal rotation (and significantly higher abduction) than their respective age-matched controls (7). In addition higher decrease in hip range of motion (possibly due to internal rotation lessening) that is strongly associated with ACL ruptures has been reported in soccer players when compared with the general population (8), whilst soccer players with re-rupture of the ACL have significantly lower mean internal-external hip rotation when compared with healthy professional soccer players (9).

Tightness within the hip external rotators will limit hip internal rotation and tightness within the hip internal rotators will limit hip external rotation (3, 4). Given that all muscles listed in Table 1 are also implicated in the execution of other hip movements, profiles of hip extension/flexion and abduction/adduction along with external/internal rotation may provide to the strength and conditioning professional a starting point for interventions on an individual basis.

REFERENCES

  1. Nunome H, Asai T, Ikegami Y, Sakurai S. Three-dimensional kinetic analysis of side-foot and instep soccer kicks. Med Sci Sports Exerc, 2002; 34:2028-2036.
  2. Brophy RH, Backus SI, Pansy BS, Lyman S, Williams RJ. Lower extremity muscle activation and alignment during the soccer instep and side-foot kicks. J Orthop Sports Phys Ther, 2007; 37:260-268.
  3. Ninos J. A chain reaction: the hip rotators. Strength Cond J, 2001; 23:26-27.
  4. Kritz MF, Cronin J. Static Posture Assessment Screen of Athletes: Benefits and Considerations. Strength Cond J, 2008; 30:18-27.
  5. Regan DP. Implications of hip rotators in lumbar spine injuries. Strength Cond J, 2000; 22:7-13.
  6. de Castro JV, Machado KC, Scaramussa K, Gomes JL. Incidence of decreased hip range of motion in youth soccer players and response to a stretching program: a randomized clinical trial. J Sport Rehabil, 2013; 22:100-107.
  7. Manning C, Hudson Z. Comparison of hip joint range of motion in professional youth and senior team footballers with age-matched controls: an indication of early degenerative change? Phys Ther Sport, 2009; 10:25-29.
  8. Gomes JL, de Castro JV, Becker R. Decreased hip range of motion and noncontact injuries of the anterior cruciate ligament. Arthroscopy, 2008; 24:1034-1037.
  9. Ellera Gomes JL, Palma HM, Ruthner R. Influence of hip restriction on noncontact ACL rerupture. Knee Surg Sports Traumatol Arthrosc, 2014; 22(1):188-91.
Recovery

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Guidelines on protein intakes for athletes are in the range of 1.2-1.7 protein·kg-1 body mass·day-1 (1). Practically the above recommendation would translate into 90-130gr of protein per day for a 75kg soccer player. However there are no established guidelines on what the respective intake should on a meal-to-meal basis. It has recently been demonstrated that muscle protein synthesis is optimized with 20 gr of ingested protein (2, 3). When higher amounts of protein were ingested these were ultimately either oxidized or excreted (2). Therefore in the above example the maximal rate of protein synthesis may be achieved with 20-25gr of protein intake in 4-6 meals. The main meals (breakfast, lunch, dinner) as well as the immediate post-exercise/post-game time are the obvious choices for protein intake. Post-exercise protein ingestion promotes maximal rates of protein synthesis (4) and ameliorates the exercise-induced symptoms of muscle damage (5).

Kostas Patras

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A less explored opportunity for protein intake is before bedtime. It has been demonstrated that ingesting slow-releasing casein immediately prior to bedtime stimulated a greater overnight response of muscle protein synthesis (6), whilst providing a combination of casein and casein hydrolysate in a 1:1 ratio before bed time augmented strength gains over a 12-week period of resistance training (7).

Practically the even distribution of protein intake throughout meals and the inclusion of a protein snack before bedtime could augment the recovery process through optimization of protein synthesis and reduction of exercise induced muscle damage.

REFERENCES

  1. Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc, 2009; 41: 709-731.
  2. Witard OC, et al. Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am J Clin Nutr, 2014: 99: 86-95.
  3. Moore DR, et al. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr, 2009: 89: 161-168.
  4. Churchward-Venne TA, Burd NA, Phillips SM. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutr Metabol (Lond), 2012; 9: 40.
  5. Jackman SR, et al. Branched-chain amino acid ingestion can ameliorate soreness from eccentric exercise. Med Sci Sports Exerc, 2010: 42: 962-970.
  6. Res PT, et al. (2012). Protein ingestion before sleep improves post-exercise overnight recovery. Med Sci Sports Exerc, 2012; 44: 1560-1569.
  7. Snijders T, et al. Protein ingestion before sleep increases muscle mass and strength gains during prolonged resistance-type exercise training in healthy young men. J Nutr, 2015; 145: 1178-1184.
Kostas Patras
Laboratory evaluation

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Laboratory assessment of endurance capacity in soccer players typically involves a treadmill at progressively increasing velocities until volitional exhaustion (1). During this test gas exchange data and blood lactate values are being collected and are used to define a range of physiological markers (lactate thresholds, maximal oxygen uptake) along with their corresponding velocities (1).

Field assessment of the speed indices involves, amongst other parameters, the assessment of maximal speed (2). The continuum of the velocities associated with the above physiological parameters as well as the inclusion of maximal sprinting speed creates a locomotor profile of the player (3) that takes into consideration submaximal and maximal physiological markers as well as neuromuscular markers (Figure 1).

  • Briefly V2 represents the velocity at aerobic threshold; up to this intensity energy is almost exclusively provided by the aerobic mechanism.
  • V4 represents the velocity at anaerobic threshold and up to this intensity the aerobic mechanism is still the major energy source. Above this intensity energy is still provided by the aerobic mechanism but there is a progressively increasing contribution from anaerobic sources.
  • Velocity at maximal oxygen uptake (or more commonly vVO2max) represents the intensity that taxes maximally the aerobic mechanism. Around and above this intensity there is a vast combination of work:rest ratios and exercise durations that provide a wide range of energy contributions from both aerobic and anaerobic sources (3, 4).
  • Finally maximal sprinting speed (MSS) represents the upper neuromuscular locomotor limit (3, 4).
Kostas Patras

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The locomotor profile can be used to assess the contribution from anaerobic sources during the various drills. For example two players with same vVO2max but different MSS will be taxed differently during a 6 min 15:15 running based HIIT at 120%vVO2max with passive rest.

Specifically despite having the same vVO2max this workout will be more intense for the player with the lower MSS. This is due to the fact that the absolute intensity of the drill (e.g. ~22 km·h-1) will be closer to upper limit of his locomotor profile. Therefore despite that the drill is taxing the aerobic mechanisms of the players to an equal extend, the player with the lower MSS is experiencing a higher anaerobic load (3, 4).

REFERENCES

  1. Ziogas GG, Patras KN, Stergiou N, Georgoulis AD. Velocity at lactate threshold and running economy must also be considered along with maximal oxygen uptake when testing elite soccer players during preseason. J Strength Cond Res, 2011; 25(2):414-419.
  2. Haugen T, Tonnessen E, Hisdal J, Seiler S. The role and development of sprinting speed in soccer. Int J Sports Physiol Perform, 2014; 9(3):432-441.
  3. Buchheit M, Laursen PB. High-intensity interval training, solutions to the programming puzzle: Part I: cardiopulmonary emphasis. Sports Med, 2013; 43(5):313-338.
  4. Buchheit M, Laursen PB. High-intensity interval training, solutions to the programming puzzle. Part II: anaerobic energy, neuromuscular load and practical applications. Sports Med, 2013; 43(10):927-54.
Kostas Patras
Injury prevention/rehabilitation

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Hip flexion plays a vital role in many athletic as well as every day life movements (1). Flexion at the hip involves the action of many different muscles (Figure 1).

Kostas Patras

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The muscles responsible for hip flexion are:

  1. Iliacus
  2. Psoas
  3. Rectus femoris
  4. Sartorius
  5. Tensor fascia lata
  6. Gluteus minimus
  7. Adductor magnus (anterior fibers)
  8. Adductor longus
  9. Adductor brevis
  10. Gracilis
  11. Pectineus

In most cases the term “hip flexors” is quite generic or even vague due to the plethora of muscles with different lever arms and therefore different potential for force production at different degrees of hip flexion (2). The study of anatomical leverages of the above muscles has been the central point of our understanding regarding their function during hip flexion. The psoas and the iliacus are the only muscles of the hip flexor group that their insertion is inferior to the pelvis (2, 3). More specifically the psoas has its origin from the length of the lumbar spine, while the iliacus originates on the posterior of the ilium (3). Therefore the psoas and the iliacus are the only muscles with a lever arm above 90º of hip flexion (2, 3). It has been proposed that in the case of a weak psoas or iliacus, the femur may move above the level of the hip, but it is not from the action of these muscles, but rather from the momentum created by the other hip flexors; that is the psoas and the iliacus are the only hip flexors capable of actively bringing the hip above 90º (4, 5).

A simple test to assess the function of the psoas and iliacus is to pull one knee to the chest and release while in a single-leg stance (2). Inability to keep the knee above 90º for 10-15 seconds indicates a weak psoas/illiacus or both (2, 5).

A more advanced test especially for athletic population would be to have your athlete stand with one foot on a plyo box so as the knee is set at above hip height (for most average height athletes this would mean a 60cm plyo box) (4). The athlete places his hands overhead or behind the head and attempt to lift the foot off the box and hold it up for 5 seconds. Inability to lift and hold is indicative of a weak psoas or iliacus, or both (4).

Kostas Patras

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REFERENCES

  1. http://www.mikereinold.com/2011/10/the-importance-of-hip-flexion-strength.html
  2. Sahrmann S. Diagnosis and Treatment of Movement Impairment Syndromes. St. Louis, MO: Mosby; 2002.
  3. Clark MA, Lucett SC. NASM’s Essentials of Corrective Exercise Training. Lippincott Williams & Wilkins, 2012.
  4. Boyle M. Advances in functional training. On Target Publications, 2010.
  5. http://www.mikereinold.com/2011/10/functional-assessment-and-exercises-to-enhance-hip-flexion.html
Kostas Patras