Del P. Wong

Hong Kong Metropolitan University

To assess the evidence for the effect of strength and conditioning on physical qualities and aesthetic competence in dance populations, three electronic databases (PubMed, Scopus, SPORTDiscus) were searched (until September 2022) for studies that met the following criteria: (i) dancers aged >16 years; (ii) structured strength and conditioning inter...

This study used an online survey to investigate strength and conditioning coaches (SCCs) demographic and job characteristics across different Chinese high–performance sports. Ninety-three SCCs from 44 high–-performance sports across 25 provinces/municipalities participated in this study (age 31.5 ± 6.9 yrs, experience as a SCC 5.5 ± 4.4 yrs). A bac...

Ramadan intermittent fasting during the COVID-19 lockdown (RIFL) may present unique demands. We investigated training practices (i.e., training load and training times) of athletes, using pre-defined survey criteria/questions, during the ‘first’ COVID-19 lockdown, comparing RIFL to lockdown-alone (LD) in Muslim athletes. Specifically, a within-subj...

Unlabelled: The COVID-19 lockdown challenged the training options of athletes worldwide, including players from the most popular sport globally, football/soccer. Purpose: The authors explored the training practices of football players worldwide during the COVID-19 lockdown. Methods: Football players (N = 2482, 30% professional, 22% semipro, an...

Purpose: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. Methods: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020...

Purpose: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. Methods: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020) a...

Objectives: Explore training-related knowledge, beliefs and practices of athletes and the influence of COVID-19-related lockdowns. Methods: Athletes [n = 12,526 classified: world-class (13%), international (21%), national (36%), state (24%), and recreational (6%)] completed an online survey (50 d; 17th May to 5th July 2020) exploring their trainin...

The present study aimed to investigate the relationship between linear deceleration performance and explosive strength capacity of the knee muscles. Fourteen female professional soccer players completed the maximal sprint deceleration tests and knee flexor (KF) and knee extensor (KE) isokinetic concentric (240° and 60°.s⁻¹) and eccentric contractio...

This study aimed to compare the neuromuscular activation of selected core musculature in supine and prone bridge exercises under stable versus suspended conditions. Forty-three healthy male participants were recruited to measure the electromyographic activities of the rectus abdominis (RA), lumbar multifidus (LM), thoracic erector spinae (TES), rec...

The aim of the present study was to compare the fitness profiles and internal training loads between senior team and academy team soccer players during an in-season phase. Twenty-two professional soccer players from the senior team (n=12; 28.3 2.0 years) and under 19 (U19) team (n=10; 18.00.4 years) of the same club participated in the present stud...

Quantifying the training content within elite professional soccer and analysis of tapering strategies has gained huge interest in recent times within the literature in order to maximise player performance. The formatting of training load tapering (TLT) appears to differ depending on the management in charge and microcycle coaching philosophy. The p...

The purpose of this study was to compare the effects of regular small-sided games (SSGreg) and SSGs combined with running drills (SSGcom) on players’ internal and external loads. Eighteen young male soccer players (average age: 18.2 ± 0.5 years) participated in 3 vs. 3 and 4 vs. 4 games, under both SSGreg and SSGcom conditions. SSGreg bouts were pl...

This study describes the contemporary practices of strength and conditioning coaches in professional soccer. Fifty-two strength and conditioning coaches from professional leagues across 18 countries completed an online survey, consisting of 45 questions, with eight sections: (a) background information, (b) muscular strength and power development, (...

This study determined the acute changes in kinematics and kinetics when an additional load equivalent to 5% body mass was attached to the torso during change of direction (COD). In this within-subject repeated measures study, 14 male soccer players (age: 18.29 ± 0.32 years) volunteered to participate. Subjects performed COD under two conditions in...

This study compared the effects of eight-week tyre flipping training intervention using light and heavy tyres on physical fitness performance. Twenty-nine young physically active males were divided into light (n = 15) and heavy (n = 14) tyre flipping groups evenly according to body weight and height. Body-to-tyre weight ratios were 0.61 ± 0.06 for...

The study purposes were to record the lower extremity sagittal and frontal joint moments and powers during gait initiation (GI); evaluate GI support moments in both planes; and analyze planar energy patterns in a group of 15 healthy, young adults. 3D motion and ground reaction force data were used to calculate support moments (SM) and joint moments...

The study aimed to: (1) investigate physical and technical performance among players during six consecutive phases of a competitive season, (2) determine if levels of match running and technical performance between the 1st and 6th phases of a season can be maintained, (3) and determine which phase features the lowest and highest values for variable...

Ho, IMK, Luk, JTC, Ngo, JK, and Wong, DP. Effects of different intraset rest durations on lifting performance and self-perceived exertion during bench press exercise. J Strength Cond Res 35(8): 2114-2120, 2021-This study compared the number of successful repetitions, failure rates, and ratings of perceived exertion (RPEs) among intraset rest (ISR)...

This study aimed to identify the effects of different pitch configurations on youth players positional and physical performances. Forty players participated in a Gk + 5vs5 + Gk small-sided game under four conditions: regular condition (regular), pitch with the direction of competitive matches; sided condition (sided), goals were changed to width; d...

The aim of this study was to identify the effects of adding spatial references during football small-sided games in youth players' tactical and physical performance. Twelve under-15 players performed a Gk + 6v6+ Gk game under two playing conditions: (i) without spatial references (CONTROL condition); (ii) with spatial references, by dividing equall...

The aim of this study was to identify the effects of a complementary training program based on differential learning approach in the physical, technical, creative and positioning performance of youth football attackers. Fifteen players were allocated into the control (U15C = 9, age: 13.9±0.5 years; U17C = 6, age: 16.1±0.7 years) and the experimenta...

This study aimed to evaluate the effectiveness and practicality of a cooling intervention with a newly designed cooling vest on heat strain attenuation in the construction industry. Fourteen construction workers volunteered to participate in the field study. Each participant took part in two trials, i.e., cooling and control. Construction work incl...

This study examined the effects of induced mental and muscular fatigue on soccer players’ physical activity profile and collective behavior during small-sided games (SSG). Ten youth soccer players performed a 5vs5 SSG under three conditions: a) control, playing without any previous activity; b) muscular fatigue, playing after performing a repeated...

Success in soccer is much dependent on how players and teams create and restrict space and time. In match situations, players constitute small sub-groups to improve their collective synchronization and achievement of specific goals. This study aimed to identify changes in the effective playing space (EPS, defined as the smallest polygonal area deli...

While continuous cooling strategies may induce some ergonomic problems to occupational workers, cooling between work bouts may be an alternative for cooling them down in hot environments. The purpose of this study was to assess if wearing a newly designed hybrid cooling vest (HCV) between two bouts of exercise improved subsequent exercise performan...

This study examined the effects of mental fatigue and additional corridor and pitch sector lines on players' physical and tactical performances during soccer small-sided games. Twelve youth players performed four Gk+6vs6+Gk small-sided games. Prior to the game, one team performed a motor coordination task to induce mental fatigue, while the other o...

This study's aim was to investigate the test-retest reliability of the 3-min all-out running test (3MRT) in hot environments. Twelve male sprinters (age 21.2 ± 1.8 years; height 1.78 ± 0.01 m; weight 71.0 ± 1.6 kg; [Formula: see text] 55.0 ± 1.0 mL kg(-1) min(-1)) performed an incremental exercise test in a laboratory, during which the first and se...

Background: Orthotic insoles that are made of foam material often have less breathability and thus cause discomfort to the wearer. Given that a sandwich structure offers better porosity and breathability that would improve comfort, the impact of custom-made insoles made with three-dimensional spacer fabric is studied. Objectives: To examine the...

This study aims to evaluate the effectiveness of a newly designed construction uniform in combating heat stress. Ten male volunteers performed treadmill running in a climatic chamber maintained at 34.5 °C temperature, 75% relative humidity, 0.3 m/s air velocity, and solar radiation of 450 W/m2 that simulates typical summer working environment of co...

Purpose: This study investigated the effects of different bout durations on internal and external loads of young soccer players during different small-sided games (SSGs). Method: Fifteen male young soccer players (average age 17 ± 1 years) participated in 2 vs 2, 3 vs 3 and 4 vs 4 SSGs. All games lasted 12 min playing time in total, but each SSG...

Common methods to estimate vertical jump height (VJH) are based on the measurements of flight time (FT) or vertical reaction force. This study aimed to assess the measurement errors when estimating the VJH with flight time using photocell devices in comparison with the gold standard jump height measured by a force plate (FP). The second purpose was...

The aim of this study was to investigate the effect of time-of-day on oxidative stress, cardiovascular parameters, muscle damage parameters, and hormonal responses following the level-1 Yo-Yo intermittent recovery test (YYIRT). A total of 11 healthy subjects performed an intermittent test (YYIRT) at two times-of-day (i.e., 07:00 h and 17:00 h), wit...

The elderly are prone to stair descent falls under low illumination. Tai Chi, a traditional Chinese conditioning exercise, has been proved to improve body stability by altering body condition, gait, and proprioception. This study investigates whether Tai Chi exercise could improve body stability during stair descent under high and low illumination....

Cooling treatment is regarded as one of good practices to provide safe training conditions to athletic trainers in the hot environment. The present study aimed to investigate whether wearing a commercial lightweight and portable hybrid cooling vest that combines air ventilation fans with frozen gel packs was an effective means to reduce participant...

Background:: The midsole is an essential assembly of footwear for retaining the shape of the shoe, delivering support to the foot, and serving as a cushioning and stability device for walking. To improve leg muscle balance and muscle co-contraction, we propose a new midsole design for high heels with different hardness levels at the forefoot regio...

Background Turning during locomotion involves considerable changes of the body’s center of mass and reduced stability, as well as lower limb kinematics and kinetics. However, many previous studies have been carried out to evaluate the effectiveness and applications of orthotic insoles as well as different types of orthotic materials in various clin...

The aim of the present study was to examine the reproducibility of the physical activity during different sided games in elite soccer players during different training sessions. Twenty elite soccer players belonging to a French first league team (age: 24.3 ± 3.2 years; height: 178.1 ± 4.2 cm; body mass: 76.9 ± 4.3 kg) participated in different smal...

We studied the relationship between daily training load (TL) experienced by professional soccer players and the Hooper questionnaire reflecting their perceived quality of sleep, fatigue, stress and delayed onset muscle soreness. During a 16-week training period, the rating of perceived exertion and duration were collected after each training sessio...

This study aimed to describe a gradient repeated sprint ability (RSA) test in comparison with a standard level one by investigating performance, metabolic demand and muscular jumping performance as a proxy for running mechanics. Eighteen athletes performed two level RSA tests (40 m × 6) - for reliability evaluation - and one ±5% gradient RSA test,...

The aim of this study was to analyse the association between physical/technical variables and the tactical prominence variables in U14 soccer matches. Twenty-two young amateur soccer players (13.5 � 0.5 years old, 5.4 � 0.5 years of practice, 163.3 � 9.8 cm in body height) from two teams of the Portuguese regional league volunteered for the study....

Objectives The aim of this study was to determine the effects of using neutral players and different task conditions in 1 vs. 1 small-sided games (SSG) on amateur soccer players’ heart rate responses and distance coverage. Equipment and methods Ten amateurs’ soccer players (26.4 ± 5.3 years old, 8.0 ± 3.2 years of practice) from a Portuguese reg...

The associations among cardiorespiratory endurance (CRE), body mass index (BMI) and blood pressure (BP) in children are still unclear. This study aimed to examine the relationships among CRE, BMI and BP in Chinese children. Data were derived from the 2010 Chinese National Survey on Students' Constitution and Health. An endurance run test was used t...

This study aimed 1)- to test the hypothesis that salivary immunoglobulin A (s-IgA) would vary with training intensity sessions (low intensity [LI] vs. high intensity sessions [HI]) during a traditional training program divided in 4 training periods and 2)- to identify key variables (e.g. GPS data, RPE, training duration) which could affect s-IgA.Sa...

Aim: The aim of this study was to compare the physical activity of players within different sided games (SSG and LSG) and with those found among elite soccer match-play. Methods: Fourteen elite soccer players (age: 23.1 years; height: 178.4 cm; weight: 73.7 kg and body fat mass 8.8%) participated in 3 competitive matches and their data were compare...

The aim of this study was to determine the effects of different formats and task conditions in small-sided conditioned games (SSCG) on young soccer players’ heart rate responses and time-motion profiles. Ten young male soccer players (age: 14.6 ± 0.8 years old; and years of practice: 4 ± 1.2) from a regional league were tested. Each player played i...

This study aimed to analyze the most prominent players' positions that contributed to the build of attack in football during FIFA World Cup 2014. The connections among teammates in all matches of the tournament were analyzed, and the tactical lineup and players' positions of players were codified as independent variables. Four centrality network me...

The use of RSA/RCOD index indicates the repeated change-of-direction (RCOD) performance relative to the repeated sprint ability (RSA), and provides a standardized approach to prioritize training needs for RSA and RCOD. To compare the RSA/RCOD index among different age groups, RSA and RCOD were measured from 20 under-16 players (U16), 20 under-19 pl...

In professional soccer, the benefits of lower limb strength training have been advocated. However, from an aspect of performance development, specifically with respect to expression of fatigue and injury prevention, the advantages of increased lower body strength have received limited attention at the elite level of the game. The primary aim of thi...

The aim of this study was to investigate the effects of the length of recovery durations between bouts in 4x4min 3--a--side small--sided games (SSG) on time--motion analysis, technical actions and physiological responses of players. Twelve young soccer players participated in 4 different 3--a--side games in which the recovery durations between bout...

This study analyzed the network characteristics of successful and unsuccessful national teams that participated in FIFA World Cup 2014. The relationship between the variables of overall team performance and the network characteristics measured on the basis of the passes between teammates was also investigated. A dataset of 37,864 passes between tea...

It has been proposed that match congestion in elite soccer results in residual fatigue and underperfor-mance in ensuing competition due to insufficient recovery time. In this article, matters relating to match congestion and running performance in elite soccer competition are discussed. We suggest a need to determine the extent to which elite playe...

Abstract This study examined the effects of a 6-week intermittent exercise training, at different intensities, on body composition, functional walking and aerobic endurance in overweight children. Forty-eight overweight children (age: 10.4 ± 0.9 years) were randomly assigned to either intervention or control group. Lower and higher intensity interm...

Elite level professional soccer players are suggested to have increased physical, technical, tactical and psychological capabilities when compared to their sub-elite counterparts. Ensuring these players remain at the elite level generally involves training many different bodily systems to a high intensity or level within a short duration. This stud...

The objective of the study was to analyze the time structure of high-level kickboxing matches. A total of 45 combats from 2 male World Championships were monitored using a time-motion analysis system. The combat time structure (i. e., high-intensity activity [HIA], low-intensity activity [LIA], and referee breaks or pauses) during competition and w...

This study aims to examine the effect of differences in the number of players and scoring method on heart rate responses, time-motion characteristics, and technical/tactical performance during small-sided soccer games. Ten male amateur soccer players (26.4 ± 5.3 years old, 8.4 ± 3.2 years of practice, 179.3 ± 5.2 cm body height, 71.2 ± 7.1 kg body...

This study compared the technical activity and physical movements of various-sided games within professional soccer. It also examined the test-retest reliability of sided games using various numbers of players. 10 elite male players from a Scottish Premier League performed small- (SSGs: 4 vs. 4), medium- (MSGs: 5 vs. 5 to 8 vs. 8) and large- (LSGs:...

It is believed that a plateau in oxygen consumption (VO2) at the end of an incremental exercise test identifies the upper limits of cardiovascular capacity. We investigated how different criteria influence the frequency with which the "plateau phenomenon" is detected and the prevalence at which "false" plateau phenomena occurs during sub-maximal ex...

Background: This study aimed to determine: 1) the changes in the physical conditioning of under-19 soccer players, 2) the effects of strength training using resistance executed as a function of the speed of a Smith machine bar, 3) relationships between heart rate (HR) values recorded during training and competition and changes in players' physical...

This study aimed to (1) quantify the respective physical workloads of bar bending and fixing; and (2) compare the physiological and perceptual responses between bar benders and bar fixers. Field studies were conducted during the summer in Hong Kong from July 2011 to August 2011 over six construction sites. Synchronized physiological, perceptual, an...

INTRODUCTION Gait initiation (GI), involving the transferring of body weight from both limbs to the stance limb and the control of forward, propelling forces, is completed once steady-state gait is achieved, reported to occur after the first step [1], the second step [2], or the third step [3-6]. To date, there have been no three-dimensional (3D) s...

The objective of the study was to analyze the time structure of high-level kickboxing matches. A total of 45 combats from two male World Championships were monitored using a time motion analysis system. The combat time structure (i.e., high-intensity activity: HIA; low-intensity activity: LIA; and referee breaks or pauses) during competition and we...

Purpose The aim of the present study was to examine the variation in physical activity of elite soccer players within successive prolonged periods of fixture congestion over 5 months of competition during the competitive season 2011-2012. Methods Sixteen international players, classified into 6 positions (central defenders: CD; full-backs: FB; cen...

Abstract The aim of this study was to examine the influence of exercise intensity and session duration on rating of perceived exertion (RPE) in adolescent Taekwondo (TKD) athletes. Twelve male youth competitive TKD athletes, aged between 13 and 18 years took part in this study. Training data (368 individual sessions) were collected during the 12 we...

The aim of this study was to compare the effects of static versus dynamic stretching on explosive performances and repeated sprint ability (RSA) following a 24-h delay. Sixteen young male soccer players performed 15-min of static stretching (SS), dynamic stretching (DS), or a no stretch control condition (CC) 24-h before performing explosive perfor...

The purpose of the present study was to compare the performance in repeated sprint ability (RSA) and repeated changes-of-direction (RCOD) among elite soccer players with different age categories. Forty-nine elite soccer players from the same club and from different age categories (Pro2: n=8; U19: n=18; U17: n=13; and U15: n=10) participated in this...