Strength and conditioning

This project, being completed by Lecturer in Applied Sport Science Conor Heeney and directed by Dr Carl Langan-Evans is focused on examining what are the key physiological and biomechanical performance indicators for different punching types in professional boxers and how this is related to when they are assessed and trained within strength and conditioning environments.

A boxing punch (categorised as jabs, crosses, hooks, and uppercuts) is a complex, high-velocity action involving biomechanical and physiological elements that transfer force from the legs through the torso and arm, ultimately culminating at the fist. Punch effectiveness depends on the coordination of these segments and execution speed, however, most of the research in this area has been conducted in amateur and not professional boxers.

Given strength and conditioning assessments and interventions to enhance sport specific punch performance can only be based on research predominantly attributed to amateur boxing athletes, this calls into question the applicability and effectiveness of these factors when considered for use with professional boxing athletes.

Firstly, this project will aim to survey and interview high level professional boxing coaches on what they perceive as the key performance indicators for different types of boxing punches, whilst subsequently testing this in the biomechanics laboratories by measuring the kinetic (forces) and kinematic (movements) outcomes of these punches.

Subsequently, the project will then examine how this relates to specific and novel tests and assessments which are regularly used within the strength and conditioning gym environment, before completing a training study to highlight a direct influence on the identified punch specific key performance indicators.

The overarching aim of this project is to demonstrate that the activities which are prescribed by strength and conditioning practitioners are specific to the needs of professional boxers and not based solely on general guidelines.

This project, funded by Sheffield Wednesday FC, is co-directed by Dr Stephen McQuilliam and Professor David Low, with Professional Doctorate student Mr Rob Lee, and investigates the implementation and effectiveness of anaerobic speed reserve (ASR) training in professional football.

The ASR — the difference between maximal sprinting speed and maximal aerobic speed (MAS) — has recently re-emerged as a framework for prescribing the supramaximal intensities characteristic of short, high-intensity interval training (HIIT), and indexes an athlete's tolerance to high-intensity exercise.

Emerging evidence indicates that, above MAS, the proportion of the ASR utilised is a more meaningful determinant of performance than intensity expressed relative to MAS alone; anchoring prescription to %ASR rather than %MAS therefore reduces inter-individual variability in physiological response.

ASR profiling consequently allows practitioners to individualise prescription, contextualise external load, and quantify the relative physiological cost of match-play outputs — capabilities of clear applied value in elite football.

The project first establishes current practices and perceptions of aerobic assessment, conditioning, and monitoring among practitioners in professional football, situating the work within applied practice. It then determines the optimal %ASR for HIIT prescription, identified as the intensity minimising the coefficient of variation in physiological response.

Finally, it examines the relationship between cumulative ASR exposure and meaningful changes in physical performance, establishing whether, and to what extent, the approach yields tangible benefits.

This project, led by a multidisciplinary team of researchers and practitioners spanning strength and conditioning, biomechanics, and nutrition, documents the rehabilitation and return-to-performance journey of elite female footballers following anterior cruciate ligament reconstruction (ACLR).

ACL injury is among the most burdensome injuries in women's football, characterised by prolonged recovery, elevated re-injury risk, and a heightened likelihood of subsequent contralateral injury. Optimal rehabilitation therefore remains a research priority, yet the literature is dominated by idealised single-athlete cases that rarely capture the inter-individual variability of applied practice.

This project addresses that gap by treating the athlete as a complex, holistic system and integrating objective field- and laboratory-based assessment within a multidisciplinary framework.

In doing so, it demonstrates how criteria-driven, individualised decision-making across disciplines can support a safe and sustainable return to performance, and how measures often overlooked in practice may refine return-to-sport criteria beyond conventional thresholds.

The project first characterises the longitudinal time-course of neuromuscular, biomechanical, and physiological recovery in each athlete, benchmarked against pre-injury and elite female normative data. It then examines how interlimb asymmetry evolves through rehabilitation and the extent to which conventional symmetry indices mask underlying movement compensations.

Finally, it illustrates how integrating multidisciplinary data streams can inform an individualised, criteria-based return-to-performance pathway attuned to each athlete's unique response to injury and reloading.

This project was led by former PhD student, Dr Elliott Hall, and was directed by Dr Rob Erskine. It was completed in collaboration with researchers and practitioners from research institutes and football clubs in the UK, Spain, Germany, Austria, Uruguay and Brazil.  

The negative impact of injury on the development of academy soccer players (ASP) means that efforts must be made to prevent and control their occurrence. Greater understanding of the factors affecting injury risk in this population could help identify and improve management of ‘at risk’ players, thus improving the likelihood of them reaching their full potential of a professional contract. Accordingly, the overriding aim of this project was to investigate the association of key risk factors with injury risk in a large cohort of high-level ASP from academies within eight professional clubs from four different countries, across two continents.  

Injuries were prospectively recorded over the course of a single season in high-level ASP to determine maturity status, playing position and/or genetic variation were associated with injury risk in ASP. The injury audit revealed that non-contact injuries to skeletal muscle were amongst those frequently recorded, with most injuries located in the lower limb. The Under-14 (U14) and U16 age groups suffered relatively more severe injuries, with minimal differences in injury rate between nations, suggesting growth and maturation may influence injury risk in this population.  

Indeed, the next study revealed that maturity status (pre-, mid- and post- peak height velocity [PHV]) was indeed associated with injury risk, where soft-tissue, ligament/tendon and thigh injuries were more prevalent in post-PHV than pre- and mid-PHV, and muscle injuries were more prevalent in post- than pre-PHV. With all injuries combined, post-PHV missed more days in the season than pre-PHV. Thus, the results from this study strongly suggest that post-PHV are at greatest risk of injury, and miss more of the season due to injury than pre- and mid- PHV. This empirical study was followed up with a review published in Sports Medicine, which highlighted the urgent need to conduct similar studies in women’s academy footballers due to the lack of high-quality research in this population.  

Having identified a maturity-dependent link with injury risk in ASP, the next study investigated whether there was an association between playing position and injuries solely in post-PHV ASP (due to the greater prevalence and severity of injuries in post- vs. pre-PHV, and the fact that playing position is more firmly defined at post-PHV). Injury incidence rate was higher in central defenders than in lateral defenders for general, soft tissue, and ligament or tendon injuries, suggesting injury prevention strategies should focus on central defenders in this population.  

Prior to this project, it was unknown if injury risk is associated with genetic variation in academy soccer players. The results from the final empirical study showed that the genetic association with injury was dependent upon maturity status: biologically younger players’ injuries were associated with connective tissue protein genes, while physically mature players’ injuries were associated with inflammation genes. This study was followed up by a literature review published in the International Journal of Sports Medicine.  

The results from this project clearly identify post-PHV players as being at higher risk of injury than their biologically younger counterparts, and that injury risk is similar between countries. The results also show that specific playing positions in physically mature ASP have a greater injury risk than others, and that genetic variation appears to be linked with the likelihood of suffering certain injuries, as well as the severity of those injuries. These novel findings could be used to help identify and manage ‘at risk’ ASP in order to reduce the burden of injury, thus increasing the chance of talented ASP reaching their full potential of a professional playing career.

Authors: Kirk C, Clark D, Langan-Evans C.

The influence of aerobic variables on mixed martial arts (MMA) performance is currently unknown. This study aimed to compare the laboratory-measured aerobic variables of MMA participants to the external load and intensity of MMA sparring bouts to determine the effect of aerobic capacity on performance.

Authors: Armstrong R, Baltzopoulos V, Langan-Evans C, Clark D, Jarvis J, Stewart C, O'Brien T.

Accentuated-eccentric loading (AEL) takes advantage of the high force producing potential of eccentric muscle contractions, potentially maximising mechanical tension within the muscle.

However, evidence is lacking on how AEL squatting may load the involved musculature, limiting scientifically justified programming recommendations. The purpose of this study was to investigate the effects of concentric and eccentric loads on joint loading and muscle activity of the lower limbs.

Authors: McQuilliam S, De Keijzer K, Jeffries A, Beato, M.

Physical tests and subjective measures, such as readiness and wellness, aid in optimising training and recovery, however, many tools lack proper validation, risking inaccurate conclusions.

This study explores physical testing and readiness practices in female football. A cross-sectional web-based survey was conducted among practitioners working with female footballers. The survey, consisting of five sections and 24 questions, examined three key areas: testing, wellness, and readiness.

A total of 51 practitioners from professional, semi-professional, and academy levels completed the survey, detailing their use of testing and monitoring data.

Elevated sport-specific physical demands and congested fixture schedules leave little recovery time and augment fatigue levels in soccer players.

Compared to traditional strength training (TST), isometric strength training (IST) may elicit comparative improvements in strength and performance-related parameters in soccer players, while reducing fatigue during periods of elevated competitive loading.

Authors: Franceschi A, Robinson MA, Owens DJ, Brownlee T, Connolly DR, Coutts AJ, Ferrari Bravo D, Enright K.

This study described the recovery responses following match play and examined the effects of manipulating training load 48h post‐match in Italian Serie A youth soccer players.

Authors: Bontemps B, Louis J, Owens DJ, Miríc S, Vercruyssen F, Gruet M, Erskine RM.

Repeated sessions of eccentric-biased exercise promote strength gains through neuromuscular adaptation. However, it remains unclear whether increasing the number of these sessions can mitigate the extent of neuromuscular fatigue and exercise-induced muscle damage (EIMD) in response to a standardised eccentric-biased bout.

Authors: Weldon A, Cloak R, Kirk C, Ruddock A, Langan-Evans C, Detanico D, Loturco I, Kons R.

The benefits of strength and conditioning (S&C) for improving judo performance and reducing injuries have been widely studied. However, the S&C practices used and perspectives held by those delivering S&C have yet to be elucidated.

Therefore, this study investigated the S&C practices and perspectives of judokas and S&C coaches working within judo.

Authors: Franceschi A, Robinson MA, Owens DJ, Brownlee T, Bampouras TM, Ferrari Bravo D, Enright K.

Microcycles are fundamental structures for training prescription and load management, helping to optimise training effects and performance. This study quantified external and internal loads of Italian Serie A youth soccer players across competitive weeks and their periodisation within microcycles.

Authors: Franceschi A, Robinson MA, Owens DJ, Brownlee T, Bampouras T, Connolly D, Ferrari Bravo D, Enright, K.

This study aimed to quantify and compare training and match load across non-congested and congested microcycles in academy football. Twenty-four under-19 Italian Serie A academy football players competing in national and international tournaments were monitored across a competitive season using external and internal load measures.

Authors: Robinson L, Murray A, Coughlan D, Ehlert A, Heeney C, Turner A, Bishop C.

This study used an individualized, case series approach to 12 weeks of strength and conditioning (S&C) training, for 3 high-level amateur and 3 professional female golfers. Each player took part in a 90-minute testing session both pre- and postintervention, and 2 structured S&C sessions per week for 12 weeks.

Movement competency assessments were used to help guide exercise selection in each intervention and test measures included golf shot data, the isometric mid-thigh pull, isometric bench press, and countermovement jump, with a total of 12 metrics across the 4 assessment protocols.

Authors: Robshaw DC, Murtagh CF, Drust B, Erskine RM.

The aims of this study were to investigate (i) differences in gastrocnemius medialis (GM) tendon properties between adult male soccer players from an English category one academy (ASP) and male control participants (CON); and (ii) the relationships between GM tendon properties and jump performance.

Authors: Hall ECR, Larruskain J, Gil SM, Lekue JA, Baumert P, Rienzi E, Moreno S, Tannure M, Murtagh CF, Ade JD, Squires P, Orme P, Anderson L, Whitworth-Turner CM, Morton JP, Drust B, Williams AG, Erskine RM.

Abstract: Our objective is to identify the most common injury types/locations in high-level male youth soccer players (YSP).

Authors: Hall ECR, Larruskain J, Gil SM, Lekue JA, Baumert P, Rienzi E, Moreno S, Tannure M, Murtagh CF, Ade JD, Squires P, Orme P, Anderson L, Whitworth-Turner CM, Morton JP, Drust B, Williams AG, Erskine RM

Abstract: Investigate if maturity status was associated with injury risk in male academy soccer players. Players were grouped by maturity offset as pre-peak height velocity (PHV), circa-PHV, post-PHV or adult. Injury prevalence proportion (IPP) and days missed were recorded for one season per player, with training and match exposure recorded in a sub-sample (n = 166).

Authors: Hall ECR, Larruskain J, Gil SM, Lekue JA, Baumert P, Rienzi E, Moreno S, Tannure M, Murtagh CF, Ade JD, Squires P, Orme P, Anderson L, Whitworth-Turner CM, Morton JP, Drust B, Williams AG, Erskine RM.

Abstract: Whether playing position influences injury in male academy soccer players (ASPs) is unclear. Our objective is to determine if playing position was associated with injury in ASPs. A total of 369 ASPs from the under-14 to under-23 age groups, classified as post-peak height velocity using maturity offset, and grouped as goalkeepers, lateral defenders, central defenders, lateral midfielders, central midfielders, or forwards.

Authors: Hall ECR and Erskine RM

Abstract: The point of fastest growth during somatic maturation is termed 'peak height velocity' (PHV), and the chronological age at which this occurs varies considerably. Academy football (soccer) players are typically categorised by chronological age, yet many children of the same age will naturally mature and grow at different ages and rates, respectively, which could affect injury risk. However, despite nearly two decades of studies investigating the association of growth and maturation with injury in academy footballers, confusion remains. 

Objective: To critically appraise the literature concerning the association of maturity timing, maturity status and growth rate with injury in academy football.

Authors: Murtagh CF, Hall ECR, Brownlee TE, Drust B, Williams AG, Erskine RM

Abstract: The aim of this review was to critically appraise the literature concerning the genetic association with athlete status, physical performance, and injury risk in soccer. The objectives were to provide guidance on which genetic markers could potentially be used as part of future practice in soccer and to provide direction for future research in this area.

Authors: Hall ECR, Larruskain J, Gil SM, Lekue JA, Baumert P, Rienzi E, Moreno S, Tannure M, Murtagh CF, Ade JD, Squires P, Orme P, Anderson L, Brownlee TE, Whitworth-Turner CM, Morton JP, Drust B, Williams AG, Erskine RM.

Abstract: It is currently unknown if injury risk is associated with genetic variation in academy soccer players (ASP). We investigated whether nine candidate single nucleotide polymorphisms were associated (individually and in combination) with injury in ASP at different stages of maturation.