Applied Sport Science in Football - Notes

Learning Outcomes

• Analyze the role of the applied Sport Scientist in professional football.
• Evaluate the job requirements for different roles within a professional football club.
• Examine the current and future issues affecting an applied sport scientist in professional football.
• Link practical understanding to complex physiology.

Historical Role of Applied Sports Science in Football

• Key early researchers included Tom Reilly (1976) and Bengt Saltin (1973).
• Jens Bangsbo (1994).
• First World Congress of Science & Football (1987) – Liverpool.
• 9th WCSF 2019 - Melbourne.
• Late 80’s early 90’s – clubs tended to use current staff with a focus on soccer-specific testing (field-based) and training.
• 2000s - Growth of technology for monitoring – e.g., Prozone & Polar HR.
• Adoption of importance of sport science was limited to a small number of coaches and players.

Current Trends

• Specialized roles within clubs.
• Increased Strength & Conditioning (S&C) in the gymnasium, prehab, strength, screening.
• Monitoring training load.
• Monitoring match load.
• Technological advances.
• ‘Big data’.
• Youth Development (biobanding?).
• Premier League Youth: Elite performance.

Structure of a Department - Roles

• First team and Academy are usually split.
• Roles:
  • Director of Performance
  • Strength & Conditioning Coach
  • Fitness Coach
  • Data Analyst
  • Nutritionist
  • Psychologist
  • Notation Analysis

Fitness Testing

• $VO_{2max}$, Lactate thresholds, Lactate steady state, Ventilatory Thresholds.
• Academy:
  • CMJ (Countermovement Jump)
  • 5-0-5 test
  • 30 m sprint
  • YoYo Intermittent Recovery Tests (Levels 1 and 2)
• First team – varies from club to club, but due to the demands of matches, screening and monitoring load are more common.
• Buchheit et al (2012) – maximum sprinting speed.
  • Maximal Aerobic Speed (MAS) – corresponds to velocity at $VO_{2max}$. Determined via a 5-minute timed run to exhaustion or a 1.5-2 km timed run.
  • $MAS = average speed for the run$
  • Anaerobic Speed Reserve – difference between max speed and MAS

Screening/Monitoring

• Body composition – skinfolds (ISAK 7 site standard).
• Biochemical markers (e.g., creatine kinase, salivary IgA).
• Jump assessments – looking for asymmetry.
  • CMJ (ballistic peak force)
  • Mid-Thigh Pull (isometric) - Dynamic Strength Index
• Norbord – eccentric hamstring strength.
• Session RPE (Rate of Perceived Exertion).
• Balance - functional movement screening.
• HR variability.
• Wellness – Sleep - questionnaires.
• Hydration – urine osmolality.
• Nutrition – diary.

Monitoring Training Load (TL)

• Volume, intensity, Absolute, Relative, Ratios.
• Variables – Distance, HR, Power, CoD (Change of Direction), Psychological - RPE.
• Acute Chronic Workload ratio (Gabbett 2004) – Training stress balance relationship between one-week training load metric and a 4-week rolling average.
• Acute divided by chronic; if ratio is > 1.5 – 2.0, then there is an increased risk of injury (Bowen et al 2019).
• Akenhead & Nassis (2016) – 48 clubs across Europe measuring 56 TL variables.

Burnley Metrics

• Total Distance - match (plus m/min).
• High-speed distance (>5.5 m/sec) (match).
• High-speed number.
• Sprint distance (> 7m/sec) (match adds in and out of possession).
• Sprint number.
• Max speed (match).
• Explosive distance.
• Accelerations – total.
• Decelerations - total.

New Metrics for 2020 Onwards

• MAS.
• $120\%$ of MAS.
• $85\%$ of peak speed.
• Horizontal force-velocity.
• Turns Individualization.

The Importance of Turns

• Turns are important in football.
• Tang et al. Sports. 2018 24;6(2):39. doi: 103390/ t6020039
• Variables:
  • Total Distance
  • No. of Runs
  • Distance of Each Run
  • Protocol Duration
  • HIR Speed
  • Decelerations
  • Accelerations

Muscle Activity During Turns

• Maasar et al. Front Physiol. 2021. 2:619447. doi: 10.3389/fphys.2021.61944
• Change of direction (CoD) vs. straight line (ST) running.
• Muscle methylome & transcriptome differences.
• PPARGC1A encodes PGC-1α, a well-established regulator of mitochondrial biogenesis.

Technology

• Massive growth in technology since the early 2000s.
• Issues – big data has arrived, but the reliability and validity of measurements at high speeds have been poor.
• Latest technology using LIDAR.

Acceleration

• Zones of Acceleration:
  • 3: $2-3 m \cdot s^{-2}$
  • 4: $3-4 m \cdot s^{-2}$
  • 5: $4-5 m \cdot s^{-2}$
  • 6: >5 m \cdot s^{-2}
• Research has consistently used high as > 2.5 m \cdot s^{-2} and very high as > 3.5 m \cdot s^{-2}.
• Akenhead et al (2013) and Buchheit et al (2014) demonstrated that anything >4 m \cdot s^{-2} showed extremely poor reliability and validity.

Lancaster's Research in Elite Football

• Total number of turns per game varies by position.

What Turns do Players Do?

• Turns throughout the season from $0-180^\circ$.
• Entry speed ($ms^{-1}$) : Low Entry Speed: $<3 ms^{-1}$, Medium Entry Speed: $3-5.5 ms^{-1}$, High Entry Speed: $5.5-7 ms^{-1}$, Very High Entry Speed: $>7 ms^{-1}$

How to Apply Research in Practice

• Drill design that focuses primarily on $125-130^\circ$ turns to reflect the findings which highlight high incidence rates within this turn bracket during match play.

Future Trends

• Big data requires statisticians and/or upskilling of the current and future workforce – data scientists.
• Practitioners need to be critical and analytical.
• Contextualization of metrics – in-out of possession, ball in play, pressing, formations, support play, with/without ball etc…

Skills Needed

• Practical skills and academic qualifications.
• Good statistical skills.
• Good IT skills.
• Data management and confidentiality.
• Communication – team player.
• “Dedication” (not a 9-5 job).
• Theoretical and practical knowledge of physiology.
• Willingness to “learn” (hierarchical).
• Critical and analytical approach.

Reading

• Akenhead, R., Hayes, P.R., Thompson, K.J. and French, D. (2013) Diminutions of acceleration and deceleration output during professional football match play. Journal of Sci & Med in Sport, 16 (6), 556-561.
• Akenhead, R. and Nassis, G.P. (2016) Training Load and Player Monitoring in High-Level Football: Current Practice and Perceptions. Int J Sports Perform, 5, 587-593.
• Buchheit, M., Al Haddad, H., Simpson, B.M., Palazzi, D., Bourdon, P.C., Di Salvo, V and Mendez- Villaneuva, A. (2014) Monitoring Accelerations With GPS in Football: Time to Slow Down? Int J Sports Perform, 9 (3), 442-445
• Buchheit, M., Simpson, B. M., Peltola, E., & Mendez-Villanueva, A. (2012). Assessing maximal sprinting speed in highly trained young soccer players. Int J Sports Physiol Perform, 7, 76-78.
• Gabbett, T.J. (2004). Incidence of injury in junior and senior rugby league players. Sports Medicine, 34, 849-859.
• Turner, A.N., Walker, S., Stembridge, M., Coneyworth, P,. Reed, G,. Birdsley, L., Barter, P and Moody, J. (2011 A testing battery for the assessment of Fitness in soccer players. Strength and Conditioning Journal, 33 (5), 29-39.