Although a large body of evidence exists documenting the ergogenic properties of caffeine, most studies have focused on endurance performance. However, findings from endurance sports cannot be generalized to performance in ball games where, apart from having a high level of endurance, successful athletic performances require a combination of physiological, technical and cognitive capabilities. The purpose of this review was to critically evaluate studies that have examined the effect of a single dose of caffeine in isolation on one or more of the following performance measures: total distance, sprint performance, agility, vertical jump performance and accuracy in ball games. Searches of three major databases resulted in 19 studies (invasion games: 13; net-barrier games: 6) that evaluated the acute effects of caffeine on human participants, provided the caffeine dose administered, and included a ball games specific task or simulated match. Improvements in sprint performance were observed in 8 of 10 studies (80%), and vertical jump in 7 of 8 studies (88%). Equivocal results were reported for distance covered, agility and accuracy. Minor side effects were reported in 4 of 19 studies reviewed. Pre-exercise caffeine ingestion between 3.0 and 6.0 mg/kg of body mass appears to be a safe ergogenic aid for athletes in ball games. However, the efficacy of caffeine varies depending on various factors, including, but not limited to, the nature of the game, physical status and caffeine habituation. More research is warranted to clarify the effects of caffeine on performance measures unique to ball games, such as agility and accuracy. It is essential that athletes, coaches and practitioners evaluate the risk-benefit ratio of caffeine ingestion strategies on an individual case-by-case basis.

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The ability to pickup task relevant visual information during movement control is crucial in successful sport performance. Quiet eye (QE), the final fixation prior to final movement onset, has been shown to be characteristic of the visual search strategies exhibited by skilled athletes in self-paced aiming tasks. Longer QE durations were previously associated with skill and successful performance outcomes. In this study, gaze behaviour data of six expert (E) and six novice (N) ten-pin bowlers were measured using a mobile eye tracker as they completed 20 trials of two single-pin conditions each (Easy: 1-pin; Hard: 10-pin). Expert bowlers exhibited significantly longer QE durations in both conditions as compared to their less skilled counterparts. However, QE duration was not found to be significantly different as a function of accuracy nor task condition. Further detailed analysis revealed considerable variance in QE characteristics between individuals, warranting the need to explore individualized interventions centered on the development of perceptual-motor control during selfpaced aiming tasks. Moreover, this study raised an important methodological issue relating to the analysis of trials with the absence of QE.

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Chelladurai (1978) developed the Multidimensional Model of Leadership, which was designed to be situation-specific to examine leadership behavior and effectiveness in sporting contexts. Applying Chelladurai's concept to the Singapore sporting context, this study aimed to assess the impact of congruence between perceived and preferred leadership behaviors on satisfaction with leadership among college student-athletes in Singapore. Data were collected from 185 college student-athletes enrolled in the five local tertiary institutes. The questionnaire utilized in this study consisted of the perception and preference versions of the Revised Leadership Scale for Sports (Zhang, Jensen, & Mann, 1997) and seven items measuring satisfaction with coaching leadership (Chelladurai et al., 1988). Confirmatory factor analysis and a series of hierarchical multiple regression procedures were carried out to test the psychometric properties of the leadership scale and the hypothesized relationship between congruence levels and satisfaction. Results revealed congruence of perceived and preferred behavior in social support was a significant indicator of athletes' satisfaction. Possible implications from the findings were discussed in an effort to better understand coaching effectiveness in Singapore.

Badminton is a sport characterized by high-intensity activity interspersed with short rests requiring specific physiological fitness, skills and game tactics. This study aimed to develop, describe and establish the reliability of a novel badminton intermittent exercise protocol, to simulate singles match-play (Part A) and assess match-fitness (Part B). Method:Twelve well-trained male badminton players performed a two-part protocol, mimicking the demands and activity of match-play, on two occasions with at least 72 hours recovery. Part A imitated match-play and consisted of forty stages alternating between 20 s work -receiving shuttlecocks from a launcher and ghosting (simulated) actions -and 40 s rest. Part B was an open-ended period, challenging match-fitness, designed to exhaust participants within 10 min. Physiological responses (heart rate, blood lactate and ratings of perceived exertion) (Part A and B) and time to exhaustion (Part B) were determined both times. Results: There were no differences in performance and physiological responses between trials (p > .05). The protocol demonstrated excellent reliability (intraclass correlation coefficient > 0.89) for all variables. Time to exhaustion (Part B) was 198 ± 98 s and 194 ± 82 s, respectively. Mean (Part A) and peak (Part B) heart rates were 166 ± 9; 191 ± 8 b•min -1 and 166 ± 9; 191 ± 7 b•min -1 and blood lactate concentrations (Part B) 11.8 ± 2.3 and 11.5 ± 2.1 mmol•l -1 for trials 1 and 2, respectively. Conclusion: The protocol reliably induces match-like responses and can be used to assess match-fitness for training/research purposes.

The badminton serve is an important shot for winning a rally in a match. It combines good technique with the ability to accurately integrate visual information from the shuttle, racket, opponent, and intended landing point. Despite its importance and repercussive nature, to date no study has looked at the visual search behaviors during badminton service in the singles discipline. Unlike anticipatory tasks (e.g., shot returns), the serve presents an opportunity to explore the role of visual search behaviors in movement control for self-paced tasks. Accordingly, this study examined skill-related differences in visual behavior during the badminton singles serve. Skilled (n = 12) and less skilled (n = 12) participants performed 30 serves to a live opponent, while real-time eye movements were captured using a mobile gaze registration system. Frame-by-frame analyses of 662 serves were made and the skilled players took a longer preparatory time before serving. Visual behavior of the skilled players was characterized by significantly greater number of fixations on more areas of interest per trial than the less skilled. In addition, the skilled players spent a significantly longer time fixating on the court and net, whereas the less skilled players found the shuttle to be more informative. Quiet eye (QE) duration (indicative of superior sports performance) however, did not differ significantly between groups which has implications on the perceived importance of QE in the badminton serve. Moreover, while visual behavior differed by skill level, considerable individual differences were also observed especially within the skilled players. This augments the need for not just group-level analyses, but individualized analysis for a more accurate representation of visual behavior. Findings from this study thus provide an insight to the possible visual search strategies as players serve in net-barrier games. Moreover, this study highlighted an important aspect of badminton relating to deception and the implications of interpreting visual behavior of players.