Chris Bishop

Middlesex University, UK · London Sport Institute

The prevalence of inter-limb asymmetries has been reported in numerous studies across a wide range of sports and physical qualities; however, few have analysed their effects on physical and sports performance. A systematic review of the literature was undertaken using the Medline and SPORT Discus databases, with all articles required to meet a spec...

Researchers and practitioners have highlighted the necessity to monitor jump strategy metrics as well as the commonly reported outcome measures during the countermovement (CMJ) and drop jump (DJ) tests. However, there is a risk of confusion for practitioners, given the vast range of metrics that now seem to be on offer via analysis software when co...

Background Reactive strength index (RSI) is used frequently in the testing and monitoring of athletes. Associations with sports performance measures may vary dependent on the task but a literature synthesis has not been performed. Objectives The aim of this meta-analysis was to examine associations between RSI measured during rebound jumping tasks...

The countermovement jump (CMJ) is one of the most used performance assessments in strength and conditioning. While numerous studies discuss the usability of different metrics in this test, this is often done within the context of a specific aim. However, to our knowledge, no information currently exists providing practitioners with some over-archin...

Anterior cruciate ligament (ACL) injury occurs frequently in sport and surgical reconstruction (ACLR) is often recommended to restore knee joint stability. To guide rehabilitation and determine return to sport readiness, practitioners have used a long-standing practice of calculating the limb symmetry index (LSI) in various functional, biomechanica...

The purpose of this study was to: i) assess the validity of the FlightScope Mevo+ against the TrackMan 4, and ii) determine the within-session reliability of both launch monitor systems when using a driver and 6-iron. Twenty-nine youth golfers, with a minimum of 3-years' playing experience, volunteered for this study. All golfers completed ten shot...

The countermovement jump (CMJ) and drop jump (DJ) are widely employed jump tests to evaluate an athlete's neuromuscular performance. Nevertheless, conducting both the CMJ and DJ assessments during one testing session can demand a considerable time investment that practitioners or coaches might not always have available. This study investigated whet...

Purpose: The association between vertical jump and weightlifting performance have been well established often using discrete performance measures such as jump height or peak power which provides little insight into temporal strategies. The purpose of this investigation was to identify currently unassessed temporal countermovement jump metrics and t...

This study investigated the grouped and individualized load-velocity profile (GLVP vs. ILVP) in Bulgarian split squat using Smith machine and free weight. Seventy five recreational male lifters completed two incremental loading tests of Bulgarian split squat. Mean velocity was measured by a linear-position transducer (GymAware). Linear regression e...

Background Lower limb biomechanics, including asymmetry, are frequently monitored to determine sport performance level and injury risk. However, contributing factors extend beyond biomechanical and asymmetry measures to include psychological, sociological, and environmental factors. Unfortunately, inadequate research has been conducted using holist...

Purpose: To investigate the relationships between a series of direct and indirect measures of linear and multidirectional speed performance in elite female rugby sevens players. Methods: Nineteen players from the Brazilian national team performed 40-m linear sprint and 505 change-of-direction (COD) tests on the same day. Based on the linear spri...

Background Performance in jumping and change of direction tests are good proxies to reflect the skill level during soccer-specific actions. Greater inter-leg asymmetries have been identified as a risk factor for developing acute and overuse injuries and jeopardizing soccer performance. The aim of this study was to assess the association between asy...

Box jumps are often included in training programs as an introductory exercise to novice athletes and untrained individuals and are an efficient option of lower-body explosiveness training. However, it is unclear whether the use of boxes of differing heights affect the inter-limb asymmetry during this exercise. The purpose of this study is to invest...

The aim of the present study is to determine the associations between lower-extremity muscle strength qualities and change of direction (CoD) performance. Three databases were used to perform a systematic literature search, and up to September 30 2022. From the studies that met the inclusion criteria, the Pearson’s r correlation coefficient to exam...

The relationships between asymmetries and performance or the identification of the asymmetry profile that has been routinely studied during jumping tests are largely derived from male-only and small sample size studies. Therefore, the aims of this study were: 1) to evaluate the magnitude and the direction of jump asymmetries (vertical and lateral)...

We investigated the associations and differences between dynamic strength index (DSI) calculated from different types of vertical jump (countermovement jump; CMJ and squat jump; SJ) and different isometric knee joint angles (30, 60 and 90°), and associations with force-velocity (FV) profile and its constituent variables (maximal theoretical force (...

Plyometric training is extensively used by coaches to enhance neuromuscular performance in a wide variety of sports. Due to the high demands of sprint speed and power output in elite sprinters and jumpers, sprint and jump coaches are likely to have great knowledge on this topic. Undoubtedly, this expertise is even more pronounced for Olympic coache...

The main aims of the current study were 1) to determine the main predictors of general and specific repeated-sprint ability (RSA) tests, 2) to analyze the relationships between RSA tests and independent measures of physical performance, 3) to examine whether between-age differences exist, and 4) to assess if maturation affects those mentioned above...

Exercise has emerged as fundamental therapeutic medicine in the management of cancer. Exercise improves health-related outcomes including quality of life, neuromuscular strength, physical function and body composition, and is associated with a lower risk of disease recurrence and increased survival. Moreover, exercise during or post-cancer treatmen...

BACKGROUND: Establishing the reliability of countermovement jump (CMJ) metrics over multiple weeks can be important in understanding and tracking changes in jump performance over time. However, a limited number of key performance indicators are generally retained for ease of interpretation. Fortunately, CMJ metrics are often highly correlated, whic...

Return to Sport (RTS) is a critical process for athletes recovering from an injury, and involves a variety of medical professionals including sports medicine, rehabilitation medicine, and primary health care providers. The RTS process centers around six key areas: musculoskeletal asymmetry, the musculoskeletal system, diagnostic methods, rehabilita...

The aims of this study were to: (1) analyze time and movement variability in a football (soccer) agility task performed with or without ball, both in the following situations a) reacting to the movement of two players with a single exit gate (R1), b) reacting to the movement of one player with two possible exit gates (R2) and c) not reacting to a s...

This study used an online survey to investigate the practices and perspectives of strength and conditioning coaches (SCCs) across different high-performance sports in China. The survey comprised of the following sections: (a) background information, (b) muscular strength and power, (c) speed, (d) endurance, (e) plyometrics, (f) flexibility, (g) phy...

Context: Deficits in plyometric abilities are common after anterior cruciate ligament reconstruction (ACLR). Vertical rebound tasks may provide a targeted evaluation of knee function. Objective: To examine the utility of a vertical hop test for assessing function after ACLR and establishing factors associated with performance. Design: Cross-se...

The purpose of the present study was to explore the validity and within-session reliability of the newly developed My Jump Lab application (app), which uses artificial intelligence techniques to monitor barbell velocity in real time. Twenty-seven sport science students performed 5 repetitions at 50% and 75% of their self-reported bench press one re...

The aim of this study was to verify the concurrent validity and the biological error-free reliability of a novel low-cost commercial encoder (Ergonauta I). Validity protocol involved comparisons with a custom system and other encoder commercially available (Vitruve). Reliability protocols involved inter devices and inter unit comparisons. No partic...

This article is part of a special issue on Golf, published in the Aspetar Sports Medicine Journal. It provides an overview of key challenges relating to the elite amateur and professional golfer that rarely gets acknowledged in peer-reviewed research (e.g., season structure, personal commitments at events, travel), along with some proposed solution...

The aims of this systematic review were to assess the association between physical performance and measures of golf performance, and the effects of physical training on measures of golf performance, in female golfers. A systematic literature search was conducted in PubMed, SPORTDiscus, Medline, and Cinahl. Inclusion criteria required studies to: 1)...

The aims of this study were to establish whether directional dominance is displayed during change of direction (COD) tasks across various angles, to determine the angle-variation data for the asymmetry magnitude and direction, and to analyse the relationships in COD performance (completion time and COD deficit) across tasks. Twenty-four young (U-16...

Background The heights obtained during the countermovement jump and drop jump tests have been measured by numerous studies using different calculation methods and pieces of equipment. However, the differences in calculation methods and equipment used have resulted in discrepancies in jump height being reported. Objectives The aim of this systemati...

Hamstring strain injuries (HSI) represents a significant burden in soccer. High speed running is one of the most common HSI mechanism, in particular during match congested periods. Peak force and rate of force development (RFD) of the hamstring muscles tested at long muscle length have shown reductions following fatiguing tasks. However, no study h...

Background: The reactive strength index (RSI) is meaningfully associated with independent markers of athletic (e.g., linear sprint speed) and neuromuscular performance (e.g., stretch-shortening-cycle [SSC]). Plyometric jump training (PJT) is particularly suitable to improve the RSI due to exercises performed in the SSC. However, no literature revie...

The aim of this study was to provide an updated view of the common practices, ideologies, education level, and professional environment of strength and conditioning (S&C) coaches in elite male ice hockey. Nineteen S&C coaches from professional, semi-professional and top-tier collegiate hockey teams in North America completed an anonymous online sur...

Understanding the total likely required to achieve a specific rank within a specific competition can aid in the long-and short-term preparation and tactics for performance teams. The primary objective of this investigation was to develop a set of predictive models for new weight categories across five performance zones for 3 major weightlifting com...

Assessing asymmetries and predicting performance in semiprofessional soccer players ABSTRACT 1 This study aimed to 1) detail the inter-limb asymmetries during multi-directional jumping, change of direction (COD) and for ankle dorsiflexion range of motion (DF-ROM) and 2) determine how asymmetries and performance in multi-directional jumping and ankl...

Olympic coaches are likely to have adequate knowledge and implement effective training programs. This study aimed to describe and critically examine the strength and conditioning practices adopted by Brazilian Olympic sprint and jump coaches. Nineteen Olympic coaches (age: 50.2 ± 10.8 years; professional experience: 25.9 ± 13.1 years) completed a s...

Ratios represent a single-value metric but consist of two component parts: a numerator variable and a denominator variable. Strictly speaking, a ratio is defined as: “the quantitative relation between two amounts showing the number of times one value contains or is contained by another”. When we discuss symmetry in sport science, we are generally c...

Purpose: To assess the variations in power performance and perceptual training responses and compare the physical performance of national boxing athletes qualified or not qualified for the Tokyo Olympic Games over a 7-month training period. Methods: Twelve amateur boxers from the Brazilian national team were tested 6 times across 7 months. In th...

2 30 week prospective observational cohort study 3 20 week experimental crossover study Test-retest, intra-and inter-rater reliability study 1 Question, feedback or interested to participate? Running • Popular endurance sport 1 • Offers numerous health-related benefits 2 • BUT frequently associated with injuries 3

The objectives of the present review were to: (a) map the studies analyzing bilateral asymmetries in specific (in-water tests) and non-specific (dry-land tests) swimming contexts and (b) investigate the effects of inter-limb asymmetries on swimming performance. Searches were systematically conducted on four databases. Out of 768 studies examined, 6...

In the golfing literature, clubhead speed is the most commonly reported metric to assess golf performance. However, a rise in the availability and use of launch monitor technologies in recent years has gathered a wide range of metrics for any given golf shot. In addition, with distance and dispersion (accuracy) being the outcome measures of any giv...

Background: The knee-joint isokinetic profile (KJIP) injury risk factor may be modulated by chronological age, however, comparative data for elite male soccer players aged 25 years and older is lacking. Objective: To describe and compare the knee-joint isokinetic profile (KJIP) according to the chronological age of professional male soccer players....

(1) Background: asymmetry is ubiquitous in nature and humans have well-established bilateral asymmetries in structure and function. However, there are (mostly unsubstantiated) claims that bilateral asymmetries may impair sports performance or increase injury risk. (2) Objective: to critically review the evidence of the occurrence and effects of asy...

The aim of this study was to compare the training effect of small-sided games (SSGs) played using large (SSG-L) and small (SSG-S) area per player (ApP) on speed and endurance in college soccer players. Twenty male NCAA division 1 soccer players were randomly assigned to 2 experimental training groups: SSG-L (n = 10), or SSG-S (n = 10). During the 4...

The aims of this study were: a) to investigate the effects of a unilateral training program, compared to a control group, on F-V profile in soccer players; b) to explore such effects on linear speed. Twenty-four soccer players, randomly assigned to a 6-week unilateral strength and ballistic jump training (UNI) (n = 12) or a control group (CON) (n =...

The aim of this study was to compare the peak-force (PF), peak-power (PP), and peak velocity (PV) outputs produced during half-squat (HS) and jump-squat (JS) exercises executed at 20, 40, 60, and 80% of one-repetition maximum (1RM) in the HS (HS 1RM); and to compute and compare the strength deficit (SDef) achieved in these exercises across these lo...

We assessed the changes in sprint, jump, and power parameters across the annual training cycle and tested the longitudinal correlations among these variables in top-level sprinters. Thirteen sprinters training with four different Olympic sprint coaches were sequentially assessed over 14 months, consecutive training camps. Performance tests were con...

The aim of this brief narrative review is to summarize the present evidence, provide recommendations for data analysis, and appropriate training methods to reduce strength and power asymmetries within athlete populations. Present evidence shows that a strong interest in the assessment of asymmetry exists. Despite the perceived associated relationsh...

The aims of this study were: a) to investigate the effects of a unilateral training program in reducing inter-limb asymmetry in male soccer players; b) to explore such effects on measures of physical performance and unilateral inter-limb asymmetry. Twenty-four soccer players, randomly assigned to a 6-week unilateral strength and power training (UNI...

The primary aim of this narrative review was to outline the historical genesis of resistance training strategies that incorporate high-load, low-velocity exercises and low-load, high-velocity exercises in the same training session allowing for different "exercise sequences" to be simultaneously implemented. Discrepancies between scientific works an...

Besides examining upper and lower limb morphological and functional asymmetry magnitudes, this study examined the relationship between lean mass and functional asymmetry in terms of magnitude and direction in 41 youth tennis players versus 41 controls. Asymmetry magnitude was determined based on anthropometric measurements (circumferences, widths),...

The aim of this study was to determine the optimal velocity loss (VL) threshold that maximises the post activation potentiation (PAP) stimulus for achieving larger and more consistent performance gains in track and field athletes. Twenty-two athletes from athletics participated in four back squat PAP tests with four different VL threshold (5%, 10%,...

The aim of the present study was to analyse the validity and reliability of the newly developed My Jump Lab smartphone app, which includes the option to calculate time to takeoff and the reactive strength index modified (RSI_Mod-calculated as jump height divided by time to takeoff), in addition to jump height. Twenty-seven postgraduate sport scienc...

The aims of the current study were to: 1) determine between-session reliability of peak force during the Nordic hamstring exercise (NHE) in professional soccer players during the pre-season, and 2) determine the subsequent magnitude and direction of peak force asymmetry from the NHE between all test sessions. The NHE was used as a weekly monitoring...

Velocity-based training is often applied to ballistic exercises, like the barbell jump squat, to improve vertical jump performance. However, determining the ideal training load based on velocity data remains difficult, as load prescriptions tend to be limited to subjective velocity loss thresholds, velocity ranges, or both. Using data from jump squ...

Historically, golf is not a sport that has a strong tradition of strength and conditioning (S&C). However, a greater understanding of the health and performance-related benefits of S&C training has resulted in players starting to take their physical fitness much more seriously. As a result, professional players are hitting the ball much further tha...

Study aim : This study examines the relationship between different magnitudes of asymmetry and their effects on speed performance. Material and methods : Forty-two sub-elite male youth soccer players performed a 30-m sprint, change of direction, single leg countermovement jump and single leg hop. Subjects were divided into groups with vertical and...

This study aimed to report seasonal variations for: 1) physical performance, 2) inter-limb asymmetry and, 3) BLD data over the course of a competitive soccer season, and determine which metrics are sensitive to change. This study used a repeated measures observational design for 19 under-20 elite academy soccer players (age: 17.58 ± 0.61 years; hei...

This study analyzed the effects of two different training programs on functional performance and inter-limb asymmetries in basketball players. Twenty-four elite youth basketball players were randomly assigned to a training program including variable unilateral horizontal movements (VUH, n = 12) or unilateral lateral movements (VUL, n = 12). Eccentr...

This study aimed to describe the bilateral deficit (BLD) during the countermovement jump (CMJ) in judo athletes and determine the relationship between the BLD and judo-specific performance. Fourteen male judo athletes participated. The athletes performed tree specific judo tests: Maximal Sprint Speed Judo Test, Maximal Aerobic Speed Judo Test, Spec...

Inter-limb asymmetries have been recently investigated in athletic populations. However, the effects of training interventions on inter-limb asymmetries have been scarcely examined. Therefore, the aim of this study was to determine the effects of training interventions on changes in inter-limb asymmetries from pre-to post-training. Furthermore, to...

Strength and conditioning (S&C) is implemented across various sports and levels, but there is limited understanding of the personnel responsible for this, including their S&C practices and perspectives. Whereas recent evidence has shown that coaches and players are often tasked with the responsibility. Therefore, this study aimed to investigate: 1)...

This study sought to investigate the inter-relationship between different vertical and horizontal variants of reactive strength index (RSI) and change of direction performance. Thirty-one male volleyball players (age: 22.4 ± 3.9 years), performed bilateral drop jumps (DJ), bilateral and unilateral countermovement jumps (CMJ), and triple hops for di...

This study aimed to compare the post-activation performance enhancement induced by successive drop-jumps performed on hard or sand surfaces in the sprint and jump performance of top-level sprinters. Athletes were tested on 2 occasions. On each visit they were allocated to one of the experimental protocols, which consisted of performing 2x5 drop-jum...

This study aimed to examine the frequency and modes of psychological priming techniques and strategies being implemented by athletes of a variety of performance levels. A 15-question, anonymous questionnaire was developed and shared via social media sites. The survey implemented a quantitative method approach to collect background information (e.g....

Background: This study compared the effects of performing different unilateral combined training interventions on diverse vertical and horizontal jumping performance parameters, change of direction, concentric and eccentric mean power, and their associated inter-limb asymmetries in young soccer players. Methods: Forty-seven young male soccer pla...

The relationship between lean mass and functional asymmetry in terms of their magnitude and direction was examined in 22 high-level female tennis players (20.9 ± 3.6 years). Lean mass of both upper and lower extremities was examined using Dual X-ray Absorptiometry. Functional asymmetry was assessed using a battery of field tests (handgrip strength,...

The purpose of this pilot study was to investigate the effects of change-of-direction (CoD) angle (90° vs. 180°) and the inclusion of acceleration approach on total task time, CoD deficit, and agreement regarding inter-limb asymmetry direction across CoD tasks. The sample included 13 young male handball players (age: 22.4 ± 3.2 years). The CoD task...

The aims of the present study were to: 1) determine within and between-session reliability of multiple metrics obtained during the triple hop test and, 2) determine any systematic bias in both the test and inter-limb asymmetry scores for these metrics. Thirteen male youth American football athletes performed three trials of a triple hop test on eac...

(1) Background: the present study examined the isokinetic peak torque exerted by both knee extensors and flexors, anterior–posterior imbalance and the magnitude and direction of inter-limb asymmetry in professional and academy soccer players. (2) Methods: one hundred soccer players (professional = 50, elite academy = 50) volunteered to take part in...

There is global concern surrounding the current lifestyle behaviours and future health and well-being of youth (1). Levels of physical activity, aerobic and muscular fitness in youth are in decline (2) with such trends further worsened by the COVID-19 pandemic (3). Increases in obesity prevalence suggest that many youth do not develop the requisite...