Hemispheric asymmetry, cardiac response, and performance in elite archers

Previous sport research on elite athletes has shown systematic changes in psychophysiological measures, such as heart rate (HR) deceleration and hemispheric asymmetries in EEG activity, in the few seconds prior to executing a motor response. These changes are believed to be due to a more focused attention on the external environment. Using archery (an attentive state), this investigation was designed to examine: (a) whether hemispheric asymmetry and HR deceleration would occur during the aiming period, and (b) if they did, whether this would affect performance. HR and left and right temporal EEG were recorded from 28 right-handed elite archers for 16 shots. The results indicated that (a) there was no HR deceleration; (b) during the aiming period, EEG alpha activity formed the dominant frequency and this was significantly greater in the left than in the right hemisphere; (c) there were no significant right hemisphere EEG changes in spectral power from 3 s before the shot to arrow release, but there were significant left hemisphere increases at 10, 12, and 24 Hz; and (d) at 1 s prior to the shot, there were no significant right hemisphere spectral power differences between best and worst shots, but there were significant left hemisphere differences at 6, 12, and 28 Hz. The relationships among hemispheric asymmetry, HR deceleration, attentional processes, and shooting performance are discussed.     

Autonomic nervous system modulation during an archery competition in novice and experienced adolescent archers

We assessed autonomic nervous system modulation through changes in heart rate variability during an archery competition as well as archery performance by comparing novice and experienced adolescent archers. Seven novice (age 14.0 ± 8.5 years, body mass index 22.9 ± 4.3 kg · m(-2), training experience 0.4 ± 0.3 years) and ten experienced archers (age 16.5 ± 10.3 years, body mass index 22.4 ± 3.1 kg · m(-2), training experience 4.1 ± 0.9 years) volunteered. Using beat-by-beat heart rate monitoring, heart rate variability was measured for 20 s before each arrow shot during two rounds of competition. We found that, compared with novices, experienced adolescent archers: (i) take more time per shot; (ii) have a higher low frequency band, square root of the mean of squared differences between successive R-R intervals (i.e. the time elapsing between two consecutive R waves in the electrocardiogram), and percentage of successive normal-to-normal intervals greater than 50 ms; and (iii) demonstrate an increase in parasympathetic nervous system activity compared with pre-competition values. We propose that these characteristics of experienced archers are appropriate for optimal performance during competition.     

The Emergence and Development of the Sociology of Sport as an Academic Specialty

Abstract

This study examined the effects of aerobic exercise on spontaneous electroencephalographic (EEG) activity. Participants (N = 34) were asked to (a) sit quietly for a 10-min adaptation period, (b) either exercise on a cycle ergometer (n = 18) or watch a videotape (n = 16) for 15 min, and (c) sit quietly for a 10-min recovery period. EEGs were collected during the last 2 min of the adaptation period, the last 2 min of each 5-min stage of the exercise/videotape period, and the last 2 min of the recovery period. EEG power densities were combined across the alpha and beta frequency bands. The results indicated that brain activation increased (i.e., alpha activity decreased and beta activity increased) during the exercise condition and returned, to baseline following exercise. This did not occur in the nonexercise condition. Thus, the results were consistent with the opponent-process theory (Solomon, 1980) in that brain activation increased during exercise.     

Expert-novice differences in performance skills and problem representations of youth and adults during tennis competition.

Expert and novice tennis players selected from three different age groups (i.e., 10-11 years, 12-13 years, and collegiate adults) were examined for differences in performance skills (i.e., behavioral analyses of video recordings) and problem representations (i.e., verbal report analyses of tape recordings) during matched competition. Factorial analyses of variance on behavioral measures indicated that experts' performances exhibited higher levels of decision and execution than novices, regardless of age. Kruskal-Wallis tests on verbal report measures indicated that experts generated more total, varied, and sophisticated condition and action concepts than novices. Within experts, adults accessed more sophisticated problem representations than youth. Both current event and action plan profiles guided and mediated adult experts' response selections and executions, respectively. Youth experts primarily used action plan profiles to guide their response selections. Novices, regardless of age, accessed weak problem representations.     

Practice task design in team sports: Representativeness enhanced by increasing opportunities for action

Abstract This study investigated effects of manipulating the number of action possibilities in a futsal passing task to understand the representativeness of practice tasks designs. Eight male senior futsal players performed a passing task in which uncertainty on passing direction for the player in possession of the ball was increased in four conditions and compared with passing data from a competitive match. Performance during a passing task and competitive futsal performance was compared using ball speed and passing accuracy data. Ball speed data were analysed by approximate entropy (ApEn) to capture their regularity in each of the four conditions and during competitive performance. Significantly high levels of regularity were observed in predetermined passes in comparison with emergent passes (i.e., passes with high number of possibilities for action). Similar results for ball speed regularity were observed between practice tasks with a high number of possibilities for action (i.e., emergent passes) and competitive performance. Similar results were observed for passing accuracy in practice tasks with a high number of possibilities for action compared to competitive performance. Increases in the number of action possibilities during practice improved action fidelity of tasks in relation to competitive performance.     

Autonomic nervous system modulation during an archery competition in novice and experienced adolescent archers

Abstract

We assessed autonomic nervous system modulation through changes in heart rate variability during an archery competition as well as archery performance by comparing novice and experienced adolescent archers. Seven novice (age 14.0 ± 8.5 years, body mass index 22.9 ± 4.3 kg · m^?2, training experience 0.4 ± 0.3 years) and ten experienced archers (age 16.5 ± 10.3 years, body mass index 22.4 ± 3.1 kg · m^?2, training experience 4.1 ± 0.9 years) volunteered. Using beat-by-beat heart rate monitoring, heart rate variability was measured for 20 s before each arrow shot during two rounds of competition. We found that, compared with novices, experienced adolescent archers: (i) take more time per shot; (ii) have a higher low frequency band, square root of the mean of squared differences between successive R-R intervals (i.e. the time elapsing between two consecutive R waves in the electrocardiogram), and percentage of successive normal-to-normal intervals greater than 50 ms; and (iii) demonstrate an increase in parasympathetic nervous system activity compared with pre-competition values. We propose that these characteristics of experienced archers are appropriate for optimal performance during competition.     

The brain in micro- and hypergravity: The effects of changing gravity on the brain electrocortical activity

Abstract

Understanding the effects of increased and decreased gravity on central nervous system is essential for developing proper physical and cognitive countermeasures to assure safe and effective space missions and human survival in space. This short review covers the available literature on the brain electrocortical activity effects of decreased and increased gravitational force comparing to the 1g Earth conditions. Among all neuroimaging methods such as functional magnetic resonance imaging (fMRI), positron-emission tomography (PET), diffusion tensor imaging (DTI), the electroencephalography (EEG) was found to be suitable method to monitor brain electrocortical activity in the extreme environments. Due to complexity and high cost of space flight missions, ground-based models have been employed to simulate microgravity effects on human body. Surprisingly, there is very limited number of publications reporting gravity-dependent EEG spectral changes. With increased gravity there are initially increased EEG activity in higher frequencies and at around 4g appears loss of consciousness with accompanying slowing of EEG due to hypoxia. In microgravity, the most prevalent changes in EEG are faster frequencies such as alpha and beta. The results from simulated microgravity (bed rest) are pointing to changes in theta and alpha, representing signs of cortical inhibition. The changes in EEG activity in space flight are attributed to a decreased sensorimotor input while in parabolic flights short and fast transitions from hyper to microgravity presumably reflect lower arousal levels and emotional processes in microgravity. Thus, based on limited research about gravity-related changes in EEG from different environments it is difficult to draw any unequivocal conclusions. Additional systematic studies about electrocortical activity in space and parabolic flights, as well as longer bed rest studies are needed in order to advance knowledge about brain functioning in extreme conditions such as space flights.     

A Methodological Consideration for the Determination of Critical Power and Anaerobic Work Capacity

Abstract

Laboratory research in motor learning has consistently demonstrated higher retention and!or transfer when practice occurs under conditions of high contextual variety (e.g., Lee &; Magill, 1983; Newell &; Shapiro, 1976; Shea of Morgan, 1979;). In the present study, an attempt was made to determine whether a contextual variety effect could be demonstrated in a standard physical education instructional setting. During practice trials on the long and short badminton serves, male and female subjects performed under either blocked (i.e., all trials of one serve followed by all trials of the other) or varied (i.e., alternating trials of long and short serves) conditions. Retention and transfer tests (i.e., using the service area opposite that employed during the practice phase) were administered at the end of the badminton unit. Although little difference was observed in the performance of the two groups during practice, alternating-trial subjects demonstrated significantly higher retention of the short serve and significantly higher transfer of both serves than blocked-trial subjects. The performance of male and female subjects was not differentially influenced by practice structure conditions. It was concluded that a practice schedule that requires performers to change their plan of action from trial to trial may facilitate the retention and transfer of motor skills in applied instructional settings.     

Attentional focus and motor learning: a review of 15 years

Over the past 15 years, research on focus of attention has consistently demonstrated that an external focus (i.e., on the movement effect) enhances motor performance and learning relative to an internal focus (i.e., on body movements). This article provides a comprehensive review of the extant literature. Findings show that the performance and learning advantages through instructions or feedback inducing an external focus extend across different types of tasks, skill levels, and age groups. Benefits are seen in movement effectiveness (e.g., accuracy, consistency, balance) as well as efficiency (e.g., muscular activity, force production, cardiovascular responses). Methodological issues that have arisen in the literature are discussed. Finally, our current understanding of the underlying mechanisms of the attentional focus effect is outlined, and directions for future research are suggested.     

Physical Characteristics and Oxygen Utilization of Male and Female Marathon Runners

Verbal and nonverbal communication is a critical mediator of performance in team sports and yet there is little extant research in sports that involves direct measures of communication. Our study explored communication within NCAA Division I female tennis doubles teams. Video and audio recordings of players during doubles tennis matches captured the communications that took place between and during points. These recordings were coded and sequential analysis computed using the Discussion Analysis Tool software (Jeong, 2003). Results indicated that most communications were emotional (i.e., > 50%) or action statements (i.e., > 25%). Winning teams exhibited significantly different communication sequences than losing teams. In particular, winning teams had a more homogeneous model of communication, which perhaps makes message interpretation more reliable. Finally, winning teams exchanged twice as many messages as losing teams.     

Science of rugby league football: a review

The purpose of this paper is to provide a comprehensive review of the science of rugby league football at all levels of competition (i.e. junior, amateur, semi-professional, professional), with special reference to all discipline-specific scientific research performed in rugby league (i.e. physiological, psychological, injury epidemiology, strength and conditioning, performance analysis). Rugby league football is played at junior and senior levels in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs). The game is played over two 30 - 40 min halves (depending on the standard of competition) separated by a 10 min rest interval. Several studies have documented the physiological capacities and injury rates of rugby league players. More recently, studies have investigated the physiological demands of competition. Interestingly, the physiological capacities of players, the incidence of injury and the physiological demands of competition all increase as the playing standard is increased. Mean blood lactate concentrations of 5.2, 7.2 and 9.1 mmol . l(-1) have been reported during competition for amateur, semi-professional and professional rugby league players respectively. Mean heart rates of 152 beats . min(-1) (78% of maximal heart rate), 166 beats . min(-1) (84% of maximal heart rate) and 172 beats . min(-1) (93% of maximal heart rate) have been recorded for amateur, semi-professional and junior elite rugby league players respectively. Skill-based conditioning games have been used to develop the skill and fitness of rugby league players, with mean heart rate and blood lactate responses during these activities almost identical to those obtained during competition. In addition, recent studies have shown that most training injuries are sustained in traditional conditioning activities that involve no skill component (i.e. running without the ball), whereas the incidence of injuries while participating in skill-based conditioning games is low. Collaborative research among the various sport science disciplines is required to identify strategies to reduce the incidence of injury and enhance the performance of rugby league players. An understanding of the movement patterns and physiological demands of different positions at all standards of competition would allow the development of strength and conditioning programmes to meet the precise requirements of these positions. Finally, studies investigating the impact of improvements in physiological capacities (including the effect of different strength and conditioning programmes) on rugby league playing performance are warranted.     

Four weeks of high cadence training alter brain cortical activity in cyclists

ABSTRACT

Exercise at different cadences might serve as potential stimulus for functional adaptations of the brain, because cortical activation is sensitive to frequency of movement. Therefore, we investigated the effects of high (HCT) and low cadence training (LCT) on brain cortical activity during exercise as well as endurance performance.

Cyclists were randomly assigned to low and high cadence training. Over the 4-week training period, participants performed 4 h of basic endurance training as well as four additional cadence-specific exercise sessions, 60 min weekly. At baseline and after 4 weeks, participants completed an incremental exercise test with spirometry and exercise at constant load with registration of electroencephalogram (EEG).

Compared with LCT, a greater increase of frontal alpha/beta ratio was confirmed in HCT. This was based on a lower level of beta activity during exercise. Both groups showed similar improvements in maximal oxygen consumption and power at the individual anaerobic threshold.

Whereas HCT and LCT elicit similar benefits on aerobic performance, cycling at high pedalling frequencies enables participants to perform an exercise bout with less cortical activation.     

Group dynamics motivation to increase exercise intensity with a virtual partner

BackgroundThe effect of the Köhler group dynamics paradigm (i.e., working together with a more capable partner where one's performance is indispensable to the team outcome) has been shown to increase motivation to exercise longer at a strength task in partnered exercise video games (exergames) using a software-generated partner (SGP). However, the effect on exercise intensity with an SGP has not been investigated. The purpose of this study was to examine the motivation to maintain or increase exercise intensity among healthy, physically active middle-aged adults using an SGP in an aerobic exergame.MethodsParticipants (n = 85, mean age = 44.9 years) exercised with an SGP in a 6-day cycle ergometer protocol, randomly assigned to either (a) no partner control, (b) superior SGP who was not a teammate, or (c) superior SGP as a teammate (team score was dependent on the inferior member). The protocol alternated between 30-min continuous and 4-min interval high-intensity session days, during which participants could change cycle power output (watts) from target intensity to alter distance and speed.ResultsMean change in watts from a targeted intensity (75% and 90% maximum heart rate) was the primary dependent variable reflecting motivational effort. Increases in performance over baseline were demonstrated without significant differences between conditions. Self-efficacy and enjoyment were significantly related to effort in the more intense interval sessions.ConclusionUnder these conditions, no Köhler effect was observed. Exercise performance during the higher-intensity interval format is more closely related to enjoyment and self-efficacy beliefs compared to the continuous sessions.     

Science of rugby league football: A review

The purpose of this paper is to provide a comprehensive review of the science of rugby league football at all levels of competition (i.e. junior, amateur, semi-professional, professional), with special reference to all discipline-specific scientific research performed in rugby league (i.e. physiological, psychological, injury epidemiology, strength and conditioning, performance analysis). Rugby league football is played at junior and senior levels in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs). The game is played over two 30?–?40 min halves (depending on the standard of competition) separated by a 10?min rest interval. Several studies have documented the physiological capacities and injury rates of rugby league players. More recently, studies have investigated the physiological demands of competition. Interestingly, the physiological capacities of players, the incidence of injury and the physiological demands of competition all increase as the playing standard is increased. Mean blood lactate concentrations of 5.2, 7.2 and 9.1?mmol?·?l^?1 have been reported during competition for amateur, semi-professional and professional rugby league players respectively. Mean heart rates of 152 beats?·?min^?1 (78% of maximal heart rate), 166 beats?·?min^?1 (84% of maximal heart rate) and 172 beats?·?min^?1 (93% of maximal heart rate) have been recorded for amateur, semi-professional and junior elite rugby league players respectively. Skill-based conditioning games have been used to develop the skill and fitness of rugby league players, with mean heart rate and blood lactate responses during these activities almost identical to those obtained during competition. In addition, recent studies have shown that most training injuries are sustained in traditional conditioning activities that involve no skill component (i.e. running without the ball), whereas the incidence of injuries while participating in skill-based conditioning games is low. Collaborative research among the various sport science disciplines is required to identify strategies to reduce the incidence of injury and enhance the performance of rugby league players. An understanding of the movement patterns and physiological demands of different positions at all standards of competition would allow the development of strength and conditioning programmes to meet the precise requirements of these positions. Finally, studies investigating the impact of improvements in physiological capacities (including the effect of different strength and conditioning programmes) on rugby league playing performance are warranted.     

The role of preparatory heart rate deceleration on balance beam performance

Preparatory heart rate deceleration occurs in tasks with an external focus of attention and is often assumed to facilitate balance performance. However, its effects upon sport-related complex balance movements have not been studied. Heart rate patterns during the preparation period of an acrobatic element (flic-flac) on the balance beam were studied in 14 female gymnasts (M age 13.2 years). A significant heart rate deceleration was found in attempts with a fall in the consecutive acrobatic element, but not in attempts without a fall. These data suggest that preparatory heart rate deceleration may be detrimental to the performance of complex movements on the balance beam.     

全国甲A足球运动员在不同负荷状态下动脉血压与心率变化特征的实验研究

本实验通过测定全国甲级Ａ组足球运动员，在功率自行车上运动时及恢复期间心率、收缩压、舒张压、脉压差及平均动脉压的变化，发现心率、收缩压在负荷时适度平行升高，舒张压在负荷时适度下降（１２ｍｍＨｇ）．脉压差负荷时逐渐加大，平均动脉压负荷时稍有上升（１１ｍｍＨｇ），恢复期最为稳定，各项指标均在６—１２ｍｉｎ内恢复到安静水平。说明其运动潜力还很大，并指出应加强综合心功的能力训练来适应高强度训练中肌肉运动的需要。     

Structure of expert players' activity during competitive interaction in table tennis

This study analyzed the activity of expert table tennis players during a match, in reference to course of action theory (Theureau, 1992). Matches were videotaped, and the players' verbalizations as they viewed the tapes were collected a posteriori. The data was analyzed by (a) transcribing the players' actions and verbalizations, (b) decomposing their activity into elementary units of meaning, and (c) grouping the elementary units into larger sets. The results showed that the matches began with an inquiry into the specific features of the opponent's play. This was followed by reproducing the actions identified as effective during the inquiry. The results are discussed in relation to the role of training in expert performance.     

Timing of triggering in relation to the cardiac cycle in nonelite rifle shooters

This study investigated the timing of the trigger pull in relation to the cardiac cycle during air rifle shooting. Electrocardiogram) was recorded from 20 male nonelite rifle shooters in two separate testing sessions. The testing was conducted at an indoor shooting range using an optoelectronic shooting system. Each participant fired a shot in the standing position at a distance of 10 m from the target. The results showed that compared to random triggering, the shooters fired more often during the phase of 10-50% of the R wave-to-R wave (R-R) interval and less often during the phase of 50-90%. With regard to performance accuracy, the participants exhibited average or above average performance, when the shot occurred in the beginning (0-50%) and in the end (70-99%) of the R-R interval. The less optimal range for the triggering was located within the 50-70% phase of the R-R interval. The length of R-R interval (i.e., heart rate) did not affect the relation of shot placement within the cardiac cycle to the accuracy of shooting performance. The present results extend previous findings by showing that in air rile shooting the optimum firing time within the cardiac cycle may be located in the systolic phase. It is argued that the systole-diastole dichotomy is not a sufficiently accurate way to investigate the effects of shot placement in the cardiac cycle. Further research is needed to examine the extent to which the relationship between the timing of triggering within the cardiac cycle and shooting performance depends a shooter's skill level.