Physiological analysis to quantify training load in badminton

Training drills in high performance badminton-effects of interval duration on internal and external loads

Purpose: The aim of the present study was to analyze the impact of interval duration on training loads and technical skill performance in high performance badminton drills. Methods: On three experimental days, 19 internationally ranked players (13 male: 22.7 ± 3.8 years, 180 ± 6 cm, 71.5 ± 6.1 kg; 6 females: 20.4 ± 2.5 years, 168 ± 4 cm, 59.8 ± 6.0 kg) completed one of three protocols (T₁₀, T₃₀, and T₅₀) of a typical badminton specific drill, the so-called "Multifeeding" (the coach feeds shuttlecock without break in a random order) in a counterbalanced order. The protocols varied in interval duration (10, 30, and 50 s) but were matched for the rally-to-rest-ratio (1:1) and active playing time (600 s). Cardiorespiratory responses (portable spirometry, chest belt), energy metabolism (levels of blood lactate, La), rate of perceived exertion (RPE), player's kinematics (Local Positioning System), and technical skill performance (video analysis) were measured. Results: Average oxygen consumption (T₁₀ 45 ± 6; T₃₀ 46 ± 7; T₅₀ 44 ± 6 mL min^-1·kg^-1), Energy expenditure (886 ± 209; 919 ± 176; 870 ± 206 kcal h^-1), heart rate (164 ± 13; 165 ± 11; 165 ± 10 bpm) and RPE (16 ± 2; 17 ± 2; 17 ± 2) did not differ between the protocols. Respiratory exchange ratio (RER) and La significantly increased depending on interval duration (RER: 0.90 ± 0.05; 0.93 ± 0.03; 0.96 ± 0.04 and La: 3.6 ± 2.0; 5.6 ± 3.0; 7.3 ± 2.3 mmol l^-1). Stroke frequency (SF; 0.58 ± 0.05; 0.57 ± 0.05; 0.55 ± 0.06 strokes·s^-1) was similar while distance covered, and average running velocity were significantly lower for T₅₀ compared to T₁₀ (76 ± 17; 70 ± 13; 65 ± 11 m min^-1). Moreover, jump frequency in T₃₀ was higher than in T₁₀ (6.7 ± 3.1; 8.8 ± 3.8; 8.5 ± 4.2 jumps·min^-1), whereas differences in internal and external loads were not associated with changes in stroke precision (errors: 16 ± 6; 19 ± 4; 18 ± 4%; accuracy: 22 ± 6; 24 ± 8; 23 ± 8%). Conclusion: Anaerobic metabolic stimulus increases while running distance and velocity decrease, in case of longer interval durations. Even though there was no impact on stroke precision, extending the intervals beyond 30 s might impair external training load and skill performance. Consequently, interval duration should be defined carefully depending on the training goals.

Physiological demands of racket sports: a systematic review

The practice of racket sports has had an exponential growth in the last decade, along with it, the scientific interest in researching the different disciplines: badminton, padel, table tennis, tennis, and squash. However, most research has focused on the technical and tactical field. Therefore, the aim of this review is to analyze and compare the indicators of the internal load of each sport: heart rate (HR), maximum oxygen consumption (VO_2max), oxygen consumption (VO₂), and lactate (LA) in order to reset physiological references to adjust the training of the players and also use these references to propose the practice of these sports for healthy purposes to the general population. PRISMA Guidelines for Systematic Review were used to search for articles that met the inclusion criteria in three databases: Web of Science, Pubmed, and Sportdiscus. The search was performed between January 2010, and September 2022. Finally, a total 27 records were included for analysis in this study. The main findings were related to the differences in the intensity rates between sports. The highest lactate concentrations and heart values were found in badminton in the intensity of effort values (whose highest values were found in badminton) 10.11 (±4.99) mmol/L and 182.6 (±2.7) bpm respectively, whereas table tennis showed the lowest ones 1.2 (± 0.4) mmol/L, and 103.99 (±15.09) bpm, respectively. The highest mean VO₂ was found in table tennis with a value of 36.8 (±13.2) ml/kg/min and the lowest in tennis with a value of 26.6 (±2.7) ml/kg/min. The highest VO_2max was found in tennis players 58.0 (±4.6) ml/kg/min, and the lowest value was in table tennis with a value of 42.9 (±4.2) ml/kg/min. Since most of the studies were carried out on elite men players, future research should focus on amateur and women level players.

Short-Term Effects of Low-Fat Chocolate Milk on Delayed Onset Muscle Soreness and Performance in Players on a Women's University Badminton Team

This study investigated the short-term effects of low-fat chocolate milk (LFCM) consumption on delayed onset muscle soreness (DOMS) and performance in female badminton players. Seven female badminton players (23 ± 1 years; height: 163.8 ± 4.1 cm; body mass: 58.7 ± 0.9 kg) were randomly assigned to 1 week of LFCM (500 mL) or placebo (water, 500 mL) consumption in a crossover design. Participants consumed LFCM or water immediately after each training session during the 1-week intervention. Performance variables (aerobic power, anaerobic power, agility, explosive power, and maximum handgrip strength) were assessed at two separate time points: pre and post-intervention (after 1 week). In addition, the Visual Analogue Scale (VAS) was used to assess DOMS before, immediately after, and at 24 and 48 h after each training session. There were significant time effects for aerobic power, upper body explosive power, minimum anaerobic power, and time to exhaustion (TTE), which significantly increased after LFCM consumption (p < 0.05). Moreover, relative and maximum lower body power significantly (p < 0.05) increased, while rating of perceived exertion (RPE) as well as DOMS in lower extremity muscles immediately after exercise significantly decreased after LFCM consumption compared to placebo (p < 0.05). There were no significant changes in maximum anaerobic power, agility, and maximum handgrip strength (p > 0.05). LFCM, as a post-exercise beverage, may help speed recovery in female badminton players leading to increased aerobic, anaerobic, and strength performance indices, increased TTE, and decreased muscle soreness and RPE.

Recognition of Badminton Shot Action Based on the Improved Hidden Markov Model

In recent years, with the rapid development of sports, the number of people playing various sports is increasing day by day. Among them, badminton has become one of the most popular sports because of the advantages of fewer restrictions on the field and ease of learning. This paper develops a wearable sports activity classification system for accurately recognizing badminton actions. A single acceleration sensor fixed on the end of the badminton racket handle is used to collect the data of the badminton action. The sliding window segmentation technique is used to extract the hitting signal. An improved hidden Markov model (HMM) is developed to identify standard 10 badminton strokes. These include services, forehand chop, backhand chop the goal, the forehand and backhand, forehand drive, backhand push the ball, forehand to pick, pick the ball backhand, and forehand. The experimental results show that the model designed can recognize ten standard strokes in real time. Compared with the traditional HMM, the average recognition rate of the improved HMM is improved by 7.3%. The comprehensive recognition rate of the final strokes can reach up to 95%. Therefore, this model can be used to improve the competitive level of badminton players.

AIR-BT, a new badminton-specific incremental easy-to-use test

Background

Badminton is a highly demanding sport characterized by intermittent efforts with energy being provided by both the aerobic and anaerobic systems. To date, no incremental badminton field test has been developed that can be easily used by badminton coaches that requires accessible material for anyone.

Objectives

The purpose of this study was to develop a practical and reliable easy-to use intermittent endurance badminton test for estimating maximal oxygen uptake (VO_2max).

Methods

Thirty six Spanish badminton players (age: 24.1±10.3 years) performed, on different days of the same week, four incremental protocols to exhaustion in randomized order: a treadmill incremental test, a Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1) and twice the Abian intermittent recovery badminton test (AIR-BT). Oxygen uptake was determined with a breath-by-breath gas analyzer during the incremental treadmill test, and performance in the Yo-yo IR1 and AIR-BT was recorded.

Results

Significant correlations (p<0.001) for Pearson’s product moment coefficient were found between the performance in the AIR-BT and the two non-specific incremental tests (VO_2max in the Treadmill Test: r = 0.87, distance in the Yo-Yo IR1: r = 0.86). The regression equation to calculate the VO_2max from the AIR-BT time [VO_2max = 0.023*(AIR-BT time in seconds)+31.334] showed an adjusted R² of 0.76 and a SEE of 3.34 ml·kg^-1·min^-1. There was no significant difference between VO_2max obtained by the incremental treadmill test and VO_2max calculated using the regression equation (p = 0.644). A paired t-test reported no significant differences between day 1 and day 2 in the AIR-BT time (p = 0.753), the Pearson correlation coefficient between both days was: r = 0.88 (p<0.001) and the intraclass correlation coefficient was 0.875.

Conclusions

The AIR-BT is a valid and reliable on-court test for assessing VO_2max in badminton players and may be utilized by coaches and physical trainers for cross-sectional comparison of players and for evaluation of longitudinal changes.

Psychophysical health and perception of well-being between master badminton athletes and the adult Italian population

BACKGROUND AND AIM OF THE WORK

Sport participation, regular exercise and physical activity in general exert many benefits on wellness, perceived health related quality of life and social satisfaction. As the people age, physical and mental deterioration occur. Master athletes are older adults that practice different sports, such as running, swimming and badminton. This is a widespread sport practiced by over 200 million people and is one of the most exerted sport in the world. In our study we compared the health perception of Italian Badminton Master athletes and normal Italian population of same age.

METHODS

Thirty (22 males, 8 females) Master badminton athletes between 18 and 69 years old participating to 2018 edition of the Italian Master Badminton Championship were enrolled for the study. All athletes compiled a six questions questionnaire, about perceived quality of life, included in the 2014-2017 Italian surveillance database "PASSI" questionnaire and answers were compared to 18-69 y/o Italian population results included in the public database.

RESULTS

Statistically significative differences were not detected between genders of master athletes. There was only a significative better psychological perception of quality of life in younger class of master athletes (p<0.05).  A significative better perception was detected in Master athletes compared to normal Italian population.

CONCLUSIONS

Aerobic sports, such as badminton, represent positive factors for improving health, psychological wellness and social engagement. Sport has a crucial role for the positive influence on growth in youngers and on the preventive role on typical diseases of older age, such as diabetes, ischemic cardiomyopathy and mental illness.

Comparison of Energy Contributions and Workloads in Male and Female Badminton Players During Games Versus Repetitive Practices

Purpose

The aim of this study was to compare the energy contributions and workloads in men and women during badminton matches versus frequently used multi-ball smash practices.

Methods

Fourteen badminton players performed one badminton singles game and one session of smashing practice on separate days. The energy contributions were examined in terms of each individual’s three energy systems and substrate oxidation, while workloads included heart rate (HR), Player Load (PL), accelerations, decelerations, changes of direction, and jumps.

Results

(1) During games, male players exhibited higher adenosine triphosphate–phosphocreatine system contribution (E_PCr, kJ) (p = 0.008) and average rate of carbohydrate oxidation (R_CHO, g/min) (p = 0.044) than female players, while female players showed greater absolute PL (p = 0.029) and more accelerations (p = 0.005) than male players. Furthermore, players who lost performed higher relative PL (p = 0.017) than those who won. (2) Higher energy system contributions, including E_PCr (kJ) (p = 0.028), E_HLa (kJ) (p = 0.024), E_Aer (kJ) (p = 0.012), E_Tot (kJ) (p = 0.007), and R_CHO (g/min) (p = 0.0002), were seen in male players during repetitive spike practices. Male players also made greater number of jumps (p = 0.0002). (3) Players exhibited higher aerobic energy contribution (p < 0.001), mean HR (p = 0.002), and HRmax (p = 0.029) during games, while exhibiting greater anaerobic energy contribution (p < 0.001) and relative PL (p = 0.001) during repetitive practices.

Conclusion

The similarities between male and female badminton players in proportional use of the three energy systems during games and repetitive spike training indicate similar relative energy demands for both genders. However, considering the need for higher aerobic capacity in competition, it might be advisable to design appropriate work:rest ratios for repetitive practices in daily training.

Monitoring training and recovery responses with heart rate measures during standardized warm-up in elite badminton players

Purpose

To investigate short-term training and recovery-related effects on heart rate during a standardized submaximal running test.

Methods

Ten elite badminton players (7 females and 3 males) were monitored during a 12-week training period in preparation for the World Championships. Exercise heart rate (HRex) and perceived exertion were measured in response to a 5-min submaximal shuttle-run test during the morning session warm-up. This test was repeatedly performed on Mondays after 1–2 days of pronounced recovery (‘recovered’ state; reference condition) and on Fridays following 4 consecutive days of training (‘strained’ state). In addition, the serum concentration of creatine kinase and urea, perceived recovery–stress states, and jump performance were assessed before warm-up.

Results

Creatine kinase increased in the strained compared to the recovered state and the perceived recovery–stress ratings decreased and increased, respectively (range of average effects sizes: |d| = 0.93–2.90). The overall HRex was 173 bpm and the observed within-player variability (i.e., standard deviation as a coefficient of variation [CV]) was 1.3% (90% confidence interval: 1.2% to 1.5%). A linear reduction of -1.4% (-3.0% to 0.3%) was observed in HRex over the 12-week observational period. HRex was -1.5% lower (-2.2% to -0.9%) in the strained compared to the recovered state, and the standard deviation (as a CV) representing interindividual variability in this response was 0.7% (-0.6% to 1.2%).

Conclusions

Our findings suggest that HRex measured during a standardized warm-up can be sensitive to short-term accumulation of training load, with HRex decreasing on average in response to consecutive days of training within repeated preparatory weekly microcycles. From a practical perspective, it seems advisable to determine intra-individual recovery–strain responses by repeated testing, as HRex responses may vary substantially between and within players.

Effect of a Padel Match on Biochemical and Haematological Parameters in Professional Players with Regard to Gender-Related Differences

Haematological and biochemical parameters have not yet been analysed in professional padel players. The aim of this study was to determine the basal values of these parameters and to observe the effect of a simulated competition on them, including gender-related differences. A total of 14 male professional players (age: 28.2 ± 7.9 years), and 16 female professional players (age: 29.7 ± 3.7 years) participated in this study. Players were allowed to hydrate ad libitum during the matches. Haematological and biochemical values were obtained before and after a simulated competitive padel match. The men’s group showed higher baseline values in red blood cells, haematocrit, haemoglobin, urea, creatinine, uric acid, albumin, glutamic oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), lactate dehydrogenase (LDH) and creatine kinase (CK) (p < 0.01) than the women’s group. Attending to match effect, significant differences were obtained in urea, creatinine, CK and glucose (p < 0.05). Finally, the group x match interaction revealed significant differences in serum concentrations of sodium and chloride (p < 0.05). In conclusion, high-level padel matches provoke several changes in biochemical parameters related to muscle damage and protein catabolism. Recovery and fluid intake strategies could be added regarding gender. The results obtained could be due to the differences in the intensity and volume of the simulated competition.

Anthropometric and Physical Fitness Profiles of World-Class Male Padel Players

The aims of this study were to describe and compare the anthropometric and physical fitness attributes of male padel players according to their competitive level, and to establish a functional anthropometric and physical profile. A total of 60 males participated in the present study. Athletes were grouped according to competition level, forming an elite group (n = 25) and a subelite group (n = 35). Anthropometric variables, hand grip and lumbar isometric strength, flexibility, and lower-body muscular strength were measured. Elite padel players were significantly older and showed significantly lower values for the thigh and calf skinfolds, the sum of six and eight skinfolds, and the sum of lower-limb skinfolds than the subelite group. Elite padel players also had significantly lower values than subelite players for body fat percentage and thigh fat area, whilst showing significantly higher values for lumbar isometric strength. Somatotype of the elite padel players could be defined as endo-mesomorphic. Results suggest that training and talent identification of padel players should focus on their anthropometric characteristics and physical fitness, with these being different between elite and subelite athletes. Normative data could help coaches throughout the talent identification process and in the design of training programs when seeking to optimise sports performance.

Individualized Monitoring of Muscle Recovery in Elite Badminton

Purpose: Individualized reference ranges for serum creatine kinase (CK) and urea are a promising tool for the assessment of recovery status in high-level endurance athletes. In this study, we investigated the application of this approach in racket sports, specifically for the monitoring of elite badminton players during the preparation for their world championships.

Methods: Seventeen elite badminton players were enrolled of which 15 could be included in the final analysis. Repeated measurements of CK and urea at recovered (R) and non-recovered (NR) time points were used for the stepwise individualization of group-based, prior reference ranges as well as for the evaluation of classificatory performance. Specifically, blood samples were collected in the morning following a day off (R) or following four consecutive training days (NR), respectively. Group based reference ranges were derived from the same data. Error rates were compared between the group-based and individualized approaches using the Fisher exact test.

Results: Error rates were numerically lower for the individualized as compared to the group-based approach in all cases. Improvements reached statistical significance for urea (test-pass error rate: p = 0.007; test-fail error rate: p = 0.002) but not for CK (p vs. group-based: test-pass error rate: p = 0.275, test-fail error rate: p = 0.291). Regardless of the chosen approach, the use of CK was associated with lower error rates as compared to urea.

Conclusion and Practical Applications: Individualized reference ranges seem to offer diagnostic benefits in the monitoring of muscle recovery in elite badminton. The lack of significant improvements in error rates for CK is likely due to the large difference between R and NR for this parameter with error rates that are already low for the group-based approach.

Heart rate and pulmonary oxygen uptake response in professional badminton players: comparison between on-court game simulation and laboratory exercise testing

PURPOSE

Badminton is characterized by bouts of high intensity interspersed by short recovery periods. Aerobic assessment via indirect calorimetry is impractical on court because of the encumbrance of portable metabolic devices. When the relationship between heart rate (HR) and pulmonary oxygen uptake [Formula: see text] [Formula: see text] is linear, HR monitoring can provide an indirect estimation of metabolic demands on court. However, owing to the intermittent nature of badminton, the [Formula: see text] relationship will differ from that obtained in the laboratory, making its use on court questionable. The aims of this study were to (i) assess cardiorespiratory and metabolic responses during on-court badminton rally simulations at different intensities and (ii) compare [Formula: see text] relationships obtained from laboratory and on-court measurements.

METHODS

The study sample was seven professional badminton players (age 16.9 ± 2.1 years; body mass 62.8 ± 9.2 kg; stature 1.71 ± 0.09 m). [Formula: see text] HR, and other respiratory and metabolic parameters were assessed in the laboratory with an incremental intermittent Astrand-type test (IIAT) and on court during rally simulations at three different intensities.

RESULTS

Cardiorespiratory parameters measured during the rallies reached 95% of maximal IIAT values. The [Formula: see text] slope and intercept differed in the on-court and the IIAT conditions (P = 0.012 and P = 0.008, respectively).

CONCLUSIONS

The difference in [Formula: see text] regression lines between the IIAT and the on-court condition indicates that HR monitoring may not provide accurate data on the aerobic demands of specific on-court badminton tasks. HR monitoring should be preceded by an indirect calorimetry test on court to assess aerobic demands more precisely.

The impact of badminton on health markers in untrained females

The purpose of the study was to examine the health effects of 8 weeks of recreational badminton in untrained women. Participants were matched for maximal oxygen uptake (V̇O_2max) and body fat percentage and assigned to either a badminton (n = 14), running (n = 14) or control group (n = 8). Assessments were conducted pre- and post-intervention with physiological, anthropometric, motivation to exercise and physical self-esteem data collected. Post-intervention, V̇O_2max increased (P < 0.05) by 16% and 14% in the badminton and running groups, respectively, and time to exhaustion increased (P < 0.05) by 19% for both interventions. Maximal power output was increased (P < 0.05) by 13% in the badminton group only. Blood pressure, resting heart rate and heart rate during submaximal running were lower (P < 0.05) in both interventions. Perceptions of physical conditioning increased (P < 0.05) in both interventions. There were increases (P < 0.05) in enjoyment and ill health motives in the running group only, whilst affiliation motives were higher (P < 0.05) for the badminton group only. Findings suggest that badminton should be considered a strategy to improving the health and well-being of untrained females who are currently not meeting physical activity guidelines.

Testing of Badminton-Specific Endurance

Madsen, CM, Højlyng, M, and Nybo, L. Testing of badminton-specific endurance. J Strength Cond Res 30(9): 2582-2590, 2016-In the present study, a novel intermittent badminton endurance (B-ENDURANCE) test was developed and tested in elite (n = 17) and skilled (n = 9) badminton players and in age-matched physically active men (nonbadminton players; n = 8). In addition, B-ENDURANCE test-retest reproducibility was evaluated in 9 badminton players. The B-ENDURANCE test is an incremental test where each level consists of repeated sequences of badminton-specific actions toward the 4 corners of the court. The subject starts in the center of the court in front of a computer screen and within each sequence, he must, in a randomized order, complete 8 actions as dictated by the computer, providing the audiovisual input and verifying that the appropriate sensor is activated within the allocated time. Recovery time between each sequence is 10 seconds throughout the test, but the time to complete each sequence is gradually decreased until the subjects cannot follow the dictated tempo. The B-ENDURANCE test performance for elite players was better (p ≤ 0.05) compared with the skilled players and nonbadminton players. In addition, the B-ENDURANCE test performance correlated (r = 0.8 and p < 0.0001) with elite players' national single rankings. Test-retest coefficient of variation was 7.9% between the first 2 trials (i.e., without a familiarization trial) but reduced to 2.5% when comparing the second and third trials. In conclusion, the B-ENDURANCE test is relevant for the evaluation of badminton-specific endurance but at least 1 familiarization trial is recommended if the test is used for evaluation of longitudinal changes, e.g., tracking training effects.

The science of badminton: game characteristics, anthropometry, physiology, visual fitness and biomechanics

Badminton is a racket sport for two or four people, with a temporal structure characterized by actions of short duration and high intensity. This sport has five events: men's and women's singles, men's and women's doubles, and mixed doubles, each requiring specific preparation in terms of technique, control and physical fitness. Badminton is one of the most popular sports in the world, with 200 million adherents. The decision to include badminton in the 1992 Olympics Game increased participation in the game. This review focuses on the game characteristics, anthropometry, physiology, visual attributes and biomechanics of badminton. Players are generally tall and lean, with an ectomesomorphic body type suited to the high physiological demands of a match. Indeed, a typical match characteristic is a rally time of 7 s and a resting time of 15 s, with an effective playing time of 31%. This sport is highly demanding, with an average heart rate (HR) of over 90% of the player's maximal HR. The intermittent actions during a game are demanding on both the aerobic and anaerobic systems: 60-70% on the aerobic system and approximately 30% on the anaerobic system, with greater demand on the alactic metabolism with respect to the lactic anaerobic metabolism. The shuttlecock has an atypical trajectory, and the players perform specific movements such as lunging and jumping, and powerful strokes using a specific pattern of movement. Lastly, badminton players are visually fit, picking up accurate visual information in a short time. Knowledge of badminton can help to improve coaching and badminton skills.

Changes in the Game Characteristics of a Badminton Match: A Longitudinal Study through the Olympic Game Finals Analysis in Men's Singles

The goal of this study was to analyze, through a longitudinal study, the Olympic Badminton Men's singles finals from the Barcelona Games (1992) to the London Games (2012) to assess some changes of the Badminton game characteristics. Six Olympic finals have been analyzed based on the official video of the Olympic Games (OG) through the temporal structure and with a notational approach. In total, 537 rallies and 5537 strokes have been analyzed. The results show a change in the game's temporal structure: a significant difference in the rally time, rest time and number of shots per rally (all p<0.0001; 0.09 < η(2) < 0.16). Moreover, the shot frequency shows a 34.0% increase (p<0.000001; η(2) = 0.17), whereas the work density revealed a 58.2% decrease (from 78% to 30.8%) as well as the effective playing time (-34.5% from 34.7±1.4% to 22.7±1.4%). This argues for an increase in the intensity of the game and a necessity for the player to use a longer resting time to recover. Lastly, the strokes distribution and the percentage of unforced and forced mistakes did not show any differences throughout the OG analysis, except for the use of the clear. This results impact on the way the training of Badminton players should be designed, especially in the temporal structure and intensity. Key pointsBadminton game has become faster, with an important increase in the shot frequency (+34%)The effective playing time has decreased between first to last Olympic Games (-34.5%)The strokes distribution and the percentage of unforced and forced errors show no differences through the OG analysis, except for the use of the clear.

Muscle damage produced during a simulated badminton match in competitive male players

The purpose of the study was to assess the occurrence of muscle damage after a simulated badminton match and its influence on physical and haematological parameters. Sixteen competitive male badminton players participated in the study. Before and just after a 45-min simulated badminton match, maximal isometric force and badminton-specific running/movement velocity were measured to assess muscle fatigue. Blood samples were also obtained before and after the match. The badminton match did not affect maximal isometric force or badminton-specific velocity. Blood volume and plasma volume were significantly reduced during the match and consequently haematite, leucocyte, and platelet counts significantly increased. Blood myoglobin and creatine kinase concentrations increased from 26.5 ± 11.6 to 197.3 ± 70.2 µg·L(-1) and from 258.6 ± 192.2 to 466.0 ± 296.5 U·L(-1), respectively. In conclusion, a simulated badminton match modified haematological parameters of whole blood and serum blood that indicate the occurrence of muscle fibre damage. However, the level of muscle damage did not produce decreased muscle performance.

Soleus H-reflex modulation during receive stance in badminton players in the receive stance

[Purpose] This study aimed to clarify the characteristics of motor neuron excitability by examining the soleus H-reflex in the ready position adopted immediately before making a return during badminton games. [Subjects] Sixteen individuals with (badminton group) and 16 without (control group) experience of playing badminton were studied. [Methods] Each subject was instructed to take up various stances for returning a shuttlecock to measure the H- and M-waves in the soleus. [Results] The H-wave was significantly decreased when gripping a racket was held in the dominant hand than compared to just standing in the badminton group. In contrast, in the control group, no significant differences were observed between when standing and the other stances. [Conclusion] Based on these results, the excitability of spinal motor neurons may have been reduced (H-wave suppression) by badminton training to increase the instantaneous force (power training).

High-intensity stepwise conditioning programme for improved exercise responses and agility performance of a badminton player with knee pain

OBJECTIVE

To examine the effect of a high-intensity stepwise conditioning programme combined with multiple recovery measures on physical fitness, agility, and knee pain symptoms of an injured player.

DESIGN

A single case study.

SETTING

University-based conditioning training laboratory.

PARTICIPANTS

One 26-year-old male world-class badminton player (height, 190.0 cm; weight, 79.3 kg; left dominant hand; playing experience, 16 years; former world champion) with patellar tendinosis and calcification of his left knee.

HIGH-CONDITIONING STEPWISE CONDITIONING PROGRAMME

The player received seven conditioning sessions over three weeks. During the programme, there was a gradual increase in training duration and load across sessions while cold therapy, manual stretches and massage were administered after each session to minimise inflammation.

MAIN OUTCOME MEASURES

The training outcome was evaluated with three different testing methods: standard step test, badminton-specific agility test, and tension-pain rating.

RESULTS

The conditioning programme reduced knee pain symptoms and improved actual performance and cardiopulmonary fitness during the agility task. The player was able to return to sport and compete within a month.

CONCLUSIONS

A high-intensity stepwise conditioning programme improved the physical fitness while sufficient recovery measures minimised any possible undesirable effects and promoted faster return to elite level competition.

Characteristics of sway in the center of gravity of badminton players

[Purpose] To clarify the characteristics of fluctuations in the center of gravity (CoG) of badminton players by comparing them between those with high and low performance levels. [Subjects] Eight male badminton players belonging to teams ranked among the top 3 at the All Japan Badminton Championships (high-level group) and 8 playing badminton for recreation in university clubs (low-level group) were studied. [Methods] CoG sway during two- and one (dominant and non-dominant)-leg standing with the eyes open and closed were recorded for 30 seconds, using a stabilometer. [Results] With their eyes open, the CoG was maintained near the center by the high-level group, while it was displaced in the direction of the dominant leg by the low-level group, with a significant difference between the two groups. In contrast, with the eyes closed, the trace length, sway area, and X- and Y-axis sway amplitudes were greater in the low- than in high-level group, with significant differences between the two groups. [Conclusion] These results support the usefulness of standing on the non-dominant leg with the eyes closed for the evaluation of badminton players’ balance ability.

Relationship between tactics and energy expenditure according to level of experience in badminton

Research on racket sports has traditionally focused on expert players and has treated energy expenditure and tactics as independent factors. These prior studies could not assess how energy expenditure and tactics changed as a function of experience and skill. Here, the specific relationship between playing tactics and energy expenditure in badminton were assessed. Participants were classified into five stages of badminton experience on the basis of conative criteria: structural (physical abilities), technical (technical skills), and functional (tactics). The physical activity of 99 players (47 beginners, 15 intermediates, 30 advanced, and 7 experts) was measured using a three-axis accelerometer during a badminton set (21 points, no extra scoring). The results showed that physical activity (counts/sec.) ranged between about 115 (Stage 1) and 155 (Stage 5), and differed significantly across the conative stages. For Stages 2 and 4, defined by an increase in use of tactics, physical activity increased substantially. For Stage 3, defined by a decrease in use of tactics, physical activity decreased significantly. Thus, tactically-oriented play appears to be closely related to physical activity.

Gender differences in game responses during badminton match play

The aim of this study was to evaluate possible gender differences in match play activity pattern [rally duration, rest time between rallies, effective playing time, and strokes performed during a rally] and exercise intensity (heart rate [HR], blood lactate [La], and subjective ratings of perceived exertion [RPE]) during 9 simulated badminton matches in male (n = 8) and female (n = 8) elite junior (16.0 ± 1.4 years) players. Results showed significant differences (all p < 0.05; effect size (ES) = 0.80-1.56) between male and female players in the activity pattern of match play, with male players engaged in longer rallies (6.8 ± 4.8 vs. 5.7 ± 3.1 seconds), executing more strokes per rally (6.4 ± 4.8 vs. 4.7 ± 2.8) and resting more between rallies (10.5 ± 8.8 vs. 8.8 ± 7.2 seconds) than female players. No clear differences (all p > 0.05; ES = -0.33 to 0.08) were observed between female or male players in average HR (174 ± 7 vs. 170 ± 9 b·min(-1)), %HRmax (89.2 ± 4.0% vs. 85.9 ± 4.3%), La (2.5 ± 1.3 vs. 3.2 ± 1.8 mmol·L(-1)), and RPE values (14.2 ± 1.9 vs. 14.6 ± 1.8) during match play, although male players spent more time (moderate effect sizes) at intensities between 81 and 90% HRmax (35.3 ± 17.9 vs. 25.3 ± 13.6; p < 0.05; ES = 0.64) in the second game. There seemed to be a trend toward an increased playing intensity (i.e., higher HR, La, and RPE) from the first to the second game, highlighting the higher exercise intensity experienced during the last part of the match. The clear between-gender differences in activity patterns induced only slightly different physiological responses.

Table Tennis: Cardiorespiratory and Metabolic Analysis of Match and Exercise in Elite Junior National Players

Purpose:

The aim of the study was to determine the cardiorespiratory and metabolic characteristics during intense and moderate table tennis (TT) training, as well as during actual match play conditions.

Methods:

Blood lactate concentration (Lac), heart rate (HR, beats per minute [bpm]), oxygen uptake (VO2), and energy expenditure (EE) in 7 male participants of the German junior national team (age: 14 ± 1 y, weight: 60.5 ± 5.6 kg height; 165 ± 8 cm) were examined during six training sessions (TS) and during an international match. The VO2 was measured continuously with portable gas analyzers. Lac was assessed every 1 to 3 min during short breaks.

Results:

Mean (peak) values for Lac, HR, VO2, and EE during the TS were 1.2 ± 0.7 (4.5) mmol·L–1, 135 ± 18 (184) bpm, 23.5 ± 7.3 (43.0) mL·kg–1· min–1, and 6.8 ± 2.0 (11.2) METs, respectively. During match play, mean (peak) values were 1.1 ± 0.2 (1.6) mmol·L–1, 126 ± 22 (189) bpm, 25.6 ± 10.1 (45.9) mL·kg–1·min–1, and 4.8 ± 1.4 (9.6) METs, respectively.

Conclusions:

For the frst time, cardiorespiratory and metabolic data in elite junior table tennis have been documented demonstrating low cardiorespiratory and metabolic demands during TT training and match play in internationally competing juniors.

Physiological characteristics of elite and sub-elite badminton players

The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO(2max) 56.9 ml . kg(-1) . min(-1) (s = 3.7) and 59.5 ml . kg(-1) . min(-1) (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.

Anthropometric characteristics, body composition and somatotype of elite junior tennis players

OBJECTIVES

The aims of this study were to describe the anthropometric characteristics, body composition and somatotype of elite male and female junior tennis players, to compare the anthropometric data, body composition and somatotype of the first 12 elite junior tennis players on the ranking with the lower ranked players, and to establish an anthropometric profile chart for elite junior tennis players.

METHODS

A total of 123 (57 males and 66 females) elite junior tennis players participated in this study. The athletes were divided into two groups, the first 12 and the lower ranked players, according to gender. A total of 17 anthropometric variables were recorded of each subject.

RESULTS

There were no significant differences in height and weight between the first 12 and the lower ranked boys, while the first 12 girls were significantly taller than the lower ranked girls (p = 0.009). Significant differences were found for humeral and femoral breadths between the first 12 and the lower ranked girls (p = 0.000; p = 0.004, respectively). The mean (SD) somatotype of elite male junior tennis players could be defined as ectomesomorphic (2.4 (0.7), 5.2 (0.8), 2.9 (0.7)) and the mean (SD) somatotype of elite female junior tennis players evaluated could be defined as endomesomorphic (3.8 (0.9), 4.6 (1.0), 2.4 (1.0)). No significant differences were found in somatotype components between the first 12 and the lower ranked players of both genders.

CONCLUSIONS

When comparing the first 12 and the lower ranked elite junior tennis players of both genders, no significant differences were observed in any measured item for the boys. By contrast, significant differences were observed in height and humeral and femoral breadths between the first 12 and the lower ranked girls, whereby the first 12 were taller and had wider humeral and femoral breadths than the lower ranked players. These differences could influence the playing style of junior female players.

Physiological characteristics of badminton match play

The present study aimed at examining the physiological characteristics and metabolic demands of badminton single match play. Twelve internationally ranked badminton players (eight women and four men) performed an incremental treadmill test [VO(2peak = )50.3 +/- 4.1 ml min(-1) kg(-1) (women) and 61.8 +/- 5.9 ml min(-1) kg(-1) (men), respectively]. On a separate day, they played a simulated badminton match of two 15 min with simultaneous gas exchange (breath-by-breath) and heart rate measurements. Additionally, blood lactate concentrations were determined before, after 15 min and at the end of the match. Furthermore, the duration of rallies and rests in between, the score as well as the number of shots per rally were recorded. A total of 630 rallies was analysed. Mean rally and rest duration were 5.5 +/- 4.4 s and 11.4 +/- 6.0 s, respectively, with an average 5.1 +/- 3.9 shots played per rally. Mean oxygen uptake (VO(2)), heart rate (HR), and blood lactate concentrations during badminton matches were 39.6 +/- 5.7 ml min(-1) kg(-1) (73.3% VO(2peak)), 169 +/- 9 min(-1) (89.0% HR(peak)) and 1.9 +/- 0.7 mmol l(-1), respectively. For a single subject 95% confidence intervals for VO(2) and HR during match play were on average 45.7-100.9% VO(2peak) and 78.3-99.8% HR(peak). High average intensity of badminton match play and considerable variability of several physiological variables demonstrate the importance of anaerobic alactacid and aerobic energy production in competitive badminton. A well-developed aerobic endurance capacity seems necessary for fast recovery between rallies or intensive training workouts.

Anthropometric and physiological profiles of sepak takraw players

OBJECTIVES

Anthropometric and physiological profiles of national sepak takraw players were determined.

METHODS

Thirty nine players, specialising in the three playing positions (tekong/server, feeder, and killer/spiker) were divided into three age categories of under 15 (U15), under 18 (U18), and under 23 (U23) years of age. Height, weight, percent body fat (%bf), maximum oxygen consumption (Vo(2max)), range of motion (ROM), back and leg strength, and heart rate, for the estimation of oxygen consumption during matches, were recorded. Statistical analysis was performed using one way ANOVA for independent measurements and data are presented as mean+/-standard deviation.

RESULTS

The U23 players were significantly taller and heavier with significantly better ROM of the neck, trunk, and ankle joints and back and leg strength than the U15 players. No significant difference was found in %bf between the three age categories. Mean maximum heart rate during exercise was significantly higher in the U15 group when compared to the U18 and U23 groups (p<0.05). Mean Vo2max was similar between the three groups. Estimated oxygen consumption during matches was 69.1%, 68.5%, and 56.4% of Vo2max in the killer, tekong, and the feeder groups, respectively.

CONCLUSIONS

The mean height, body weight, and cardiopulmonary capacities of the players were within the Malaysian population norms, but were somewhat lower than those of players of other court games from other countries. %bf was also lower in these players. This study provides the much needed anthropometric and physiological data of sepak takraw players for further development of this sport.

Multiple sprint work : physiological responses, mechanisms of fatigue and the influence of aerobic fitness

The activity patterns of many sports (e.g. badminton, basketball, soccer and squash) are intermittent in nature, consisting of repeated bouts of brief (<or=6-second) maximal/near-maximal work interspersed with relatively short (<or=60-second) moderate/low-intensity recovery periods. Although this is a general description of the complex activity patterns experienced in such events, it currently provides the best means of directly assessing the physiological response to this type of exercise. During a single short (5- to 6-second) sprint, adenosine triphosphate (ATP) is resynthesised predominantly from anaerobic sources (phosphocreatine [PCr] degradation and glycolysis), with a small (<10%) contribution from aerobic metabolism. During recovery, oxygen uptake (V-O2) remains elevated to restore homeostasis via processes such as the replenishment of tissue oxygen stores, the resynthesis of PCr, the metabolism of lactate, and the removal of accumulated intracellular inorganic phosphate (Pi). If recovery periods are relatively short, V-O2 remains elevated prior to subsequent sprints and the aerobic contribution to ATP resynthesis increases. However, if the duration of the recovery periods is insufficient to restore the metabolic environment to resting conditions, performance during successive work bouts may be compromised. Although the precise mechanisms of fatigue during multiple sprint work are difficult to elucidate, evidence points to a lack of available PCr and an accumulation of intracellular Pi as the most likely causes. Moreover, the fact that both PCr resynthesis and the removal of accumulated intracellular Pi are oxygen-dependent processes has led several authors to propose a link between aerobic fitness and fatigue during multiple sprint work. However, whilst the theoretical basis for such a relationship is compelling, corroborative research is far from substantive. Despite years of investigation, limitations in analytical techniques combined with methodological differences between studies have left many issues regarding the physiological response to multiple sprint work unresolved. As such, multiple sprint work provides a rich area for future applied sports science research.

Validation of a field test for the non-invasive determination of badminton specific aerobic performance

AIM

To develop a badminton specific test to determine on court aerobic and anaerobic performance.

METHOD

The test was evaluated by using a lactate steady state test. Seventeen male competitive badminton players (mean (SD) age 26 (8) years, weight 74 (10) kg, height 179 (7) cm) performed an incremental field test on the badminton court to assess the heart rate turn point (HRTP) and the individual physical working capacity (PWC(i)) at 90% of measured maximal heart rate (HR(max)). All subjects performed a 20 minute steady state test at a workload just below the PWC(i).

RESULTS

Significant correlations (p<0.05) for Pearson's product moment coefficient were found between the two methods for HR (r = 0.78) and velocity (r = 0.93). The HR at the PWC(i) (176 (5.5) beats/min) was significantly lower than the HRTP (179 (5.5) beats/min), but no significant difference was found for velocity (1.44 (0.3) m/s, 1.38 (0.4) m/s). The constant exercise test showed steady state conditions for both HR (175 (9) beats/min) and blood lactate concentration (3.1 (1.2) mmol/l).

CONCLUSION

The data indicate that a valid determination of specific aerobic and anaerobic exercise performance for the sport of badminton is possible without HRTP determination.