Biomedical subjects

G Tenenbaum

Publications and source records attributed to G Tenenbaum.

At least 19 recordsLinked to original sources

PubMed2006

Information-processing under incremental levels of physical loads: comparing racquet to combat sports.

AIM: Skillful performance in combat and racquet sports consists of proficient technique accompanied with efficient information-processing while engaged in moderate to high physical effort. This study examined information processing and decision-making using simple reaction time (SRT) and choice reaction time (CRT) paradigms in athletes of combat sports and racquet ball games while undergoing incrementally increasing physical effort ranging from low to high intensities. METHODS: Forty national level experienced athletics in the sports of tennis, table tennis, fencing, and boxing were selected for this study. Each subject performed both simple (SRT) and four-choice reaction time (4-CRT) tasks at rest, and while pedaling on a cycle ergometer at 20%, 40%, 60%, and 80% of their own maximal aerobic power (Pmax). RESULTS: RM MANCOVA revealed significant sport-type by physical load interaction effect mainly on CRT. Least significant difference (LSD) posthoc contrasts indicated that fencers and tennis players process information faster with incrementally increasing workload, while different patterns were obtained for boxers and table-tennis players. The error rate remained stable for each sport type over all conditions. Between-sport differences in SRT and CRT among the athletes were also noted. CONCLUSIONS: Findings provide evidence that the 4-CRT is a task that more closely corresponds to the original task athletes are familiar with and utilize in their practices and competitions. However, additional tests that mimic the real world experiences of each sport must be developed and used to capture the nature of information processing and response-selection in specific sports.

Adolescent↗

PubMed2006

Simple and choice reaction times under varying levels of physical load in high skilled fencers.

AIM: Fencing requires rapid and accurate decision-making while competing and experiencing gradual perceived effort. This study examined the linkage between physical effort, simple reaction time and choice reaction time in fencers and non-fencer subjects. METHODS: Two age-matched groups participated in this experiment: 12 professional fencers and 12 sedentary subjects. Each subject performed both simple (SRT) and choice reaction time (CRT) tasks at rest, and while pedaling on a cycle ergometer at 20%, 40%, 60%, and 80% of their own maximal aerobic power (Pmax). RESULTS: At rest, no significant differences were found between experts and sedentary subjects neither in SRT nor CRT. The fencers showed shorter CRTs at 40%, 60% and 80% of Pmax compared to those measured at rest. In contrast, SRTs did not vary as a function of effort level. In sedentary subjects, workload did not affect SRTs and CRT. Moreover, the error rate remained stable for each group over all conditions. CONCLUSIONS: Current results showed that physical load results in enhancing information processing as measured by CRT without affecting SRT. The data provides evidence that aerobic exercise enhances attentional capability in fencers who are used to process information under similar physical conditions, but not in sedentary subjects unfamiliar to this environment. Exercise induces arousal that supports alertness to external environmental stimuli in highly trained athletes.

Adult↗

PubMed2001

Modeling of velocity regimens for anaerobic and aerobic power exercises in high-performance swimmers.

BACKGROUND: This study was aimed at investigating the validity and eligibility of a modeling method to determine velocity regimes of highly intensive swimming exercises. METHODS: The model postulates that swimming velocity regimens, which correspond to the three biomotor components, i.e.: Maximal Anaerobic Power, Anaerobic Capacity, and Aerobic Power, can be predicted by special equations using a 50 m all out swim velocity, and the equation coefficient, which determine swimmer's classification. The swimmers are classified into 12 categories according to pre-determined race distance records, and swimmer's capability level. EXPERIMENTAL DESIGN: Comparative field study was used to contrast predicted velocity regimens with observed velocity regimes. SETTINGS: National swimming center at the Wingate Institute for Physical Education. PARTICIPANTS: 22 highly trained swimmers (14 male and 8 female) participated in this study and were examined 1-4 times within a period of two years in totally 162 sessions. INTERVENTIONS: The 50 m all-out trial was performed and three basic velocity regimens were predicted according to the modeling procedure. Three different interval sets were carried out by all the swimmers for validation procedures. The blood lactate (BLA) samples were taken after test completion. RESULTS: The correlations between the observed and predicted velocities within each of the three tests were very strong. The RM-ANOVA with respect to lactic acid concentration revealed that across the three measures (different tests) BLA concentration was significantly higher in male swimmers than in female swimmers, and highest in butterfly followed by breaststroke, backstroke, and freestyle stroke. CONCLUSIONS: The modeling method allows to predict desirable velocity regimes in order to develop the main biomotor components of the swimmers. This procedure is recommended for practice as a non-invasive method for designing desired training regimens.

Adolescent↗

PubMed2000

An investigation of the dynamics of aggression: direct observations in ice hockey and basketball.

There have been significant problems in the study of sports aggression, and they are linked to how aggression has been defined, measured, and analyzed. Following a review of the whole domain, this study aimed to construct a theoretically coherent and ecologically valid framework for research on processes underlying sports aggression and to contribute to the advancement of knowledge in the area. An exploratory method using computer observational analysis as the primary research method, along with complementary questionnaires and personal reflections, considered aggression in two comparison sports: ice hockey and basketball. Data were compiled and classified by involved and independent experts relative to factors and behaviors associated with sports aggression derived from a comprehensive review of the literature. Among the study's findings were that: (a) aggression was instrumental in nature two-thirds of the time; (b) aggressive acts typically occurred in clusters and varied in frequency according to game circumstances; and (c) multiple variables and aggression theories were related to severely aggressive acts. The complex dynamics of sports aggression via similar naturalistic methodologies is discussed.

Adolescent↗

PubMed1999

Acute and residual effects of vibratory stimulation on explosive strength in elite and amateur athletes.

Fourteen elite and 14 amateur athletes were subjected to vibratory stimulation during bilateral biceps curl exercises of explosive strength exertion. The athletes performed two separate series of three sets of exercises in random order. The second set of one series was administered with superimposed vibration of 44 Hz and an acceleration of about 30 m x s(-2) transmitted through the two-arms handle to the arm muscles. The mechanical power of each repetition was measured by the 'Power Teach' instrument. The maximal and mean power values for each set were automatically recorded and shown on the screen. The acute effect was evaluated as the difference between the mean and peak power output in the second (with vibratory stimulation) and first (without vibratory stimulation) sets. Similarly, the residual effect was taken to be the difference between the power values of the third (after vibratory stimulation) and the first (before vibratory stimulation) sets. The results were subjected to a repeated-measures analysis of variance with group as a between-participants factor. The results showed that exercise mode (with vs without vibratory stimulation) resulted in a significant immediate effect for mean power and for maximal power. The factor group (elite vs amateurs) resulted in a significant effect for maximal power only. The increase in explosive strength exertion attributed to vibratory stimulation was 30.1 and 29.8 W (10.4% and 10.2%) for maximal and mean power respectively in the elite group, and 20.0 and 25.9 W (7.9% and 10.7%) respectively in the amateur athletes. Vibratory stimulation resulted in an insignificant residual effect.

Adolescent↗

PubMed1999

Perceived discomfort in running: scale development and theoretical considerations.

The aim of this study was to develop a discomfort questionnaire to elicit the feelings and thoughts of people engaged in running activities. Ten runners who completed a particularly demanding 9-km run were asked to express their feelings and thoughts during the run they had just completed. These responses were recorded and later used as the first pool of items (k = 36). The questionnaire was then given to 171 runners in different distance races throughout the 1995 competitive season. These responses were analysed using exploratory factor analytic techniques and Rasch probabilistic analysis, as well as traditional reliability and validity procedures. The final version of the questionnaire consisted of 32 items divided into eight correlated subscales: proprioceptive symptoms, leg symptoms, respiratory difficulties, disorientation, dryness and heat, task completion thoughts, mental toughness, and head or stomach symptoms. These eight categories can be collapsed into three global categories suggested by researchers of pain: sensory-discriminative, motivational-affective and cognitive-evaluative. Rasch analysis suggested that the motivational-affective and cognitive-evaluative dimensions (i.e. the psychological) are the most experienced (i.e. rated highest). The eight subscales have ecological validity and were found to alter with the demands of different running distances.

Adolescent↗

PubMed1999

An examination of mood changes and performance in a professional basketball team.

BACKGROUND: The purpose of this study was to examine the relationship between the Profile of Mood States (POMS) and performance in a professional basketball team. METHODS PARTICIPANTS: seven male professional basketball players playing for the defending champions of the Israel Basketball League participated in this study. EXPERIMENTAL DESIGN: the POMS was administered seven times (T1-T7) during the season. The initial POMS administration was performed three weeks following the start of preseason practice and one day prior to the first basketball game. Each of the other POMS administrations were performed two days following a game and no more than 2 days before the next game. RESULTS: Typical iceberg profiles were observed during T1, T2 and T3, which coincided with successful performance (winning percentages greater than 60% between each POMS administration). Subsequent decreases in performance between T3 and T4 (a 33% winning percentage) resulted in a decrease in vigor and an increase in anger. As team performance improved between T4 and T5 (winning percentage again above 60%), vigor returned to its original level. However, the mood states anger and depression remained elevated, even during successful team play. This may have been related to problems independent of basketball performance (coaching and financial). CONCLUSIONS: These results suggest that the mood state vigor may be reflective of team performance. In addition, mood states appear to be influenced more by performance or experience, rather than performance being influenced by changes in mood states.

Adult↗

PubMed1999

The flow experience: a Rasch analysis of Jackson's Flow State Scale.

Jackson and Marsh (1996) reported the development of a Flow State Scale (FSS) for use in sport and physical activity. The FSS contains 36 items measuring the nine dimensions of flow described by Csikszentmihalyi (1990, 1993). Jackson and Marsh reported high internal consistency estimates for the subscales and evidence for nine first-order factors and one second-order factor when confirmatory factor analytic techniques were used. The present study extended this validation work by subjecting the data from the original sample (N = 394) of elite younger athletes and a subsequent sample (N = 398) of older athletes to Rasch analysis. These Rasch analyses showed quite clearly that the flow dimensions may be conceptualised as a continuum with "autotelic experience" being experienced more readily than dimensions such as "transformation of time", a state that may only be encountered at the height of a deep flow experience. The Rasch analyses provide useful additional information about the areas of the flow continuum tapped by the items and scales of the FSS and, in so doing, help to confirm the construct validity and generalisability of the scale itself.

Adolescent↗

PubMed1998

Can emotive imagery aid in tolerating exertion efficiently?

BACKGROUND: The study examined the role of relaxation and aggressive types of imagery and the effect of goal orientations, self efficacy, self control, and determination on exertion tolerance. METHODS EXPERIMENTAL DESIGN: the participants underwent an exertive task in which they were required to squeeze a dynamometer, at 50% of their maximal hand-grip capacity, for as long as they could. Perceived exertion was measured every 15 sec during the task. The time that elapsed between rating exertion as "strong", and dropping the handbar under 10% of the designated 50% criterion, was considered as the "zone of exertion tolerance". PARTICIPANTS: forty-eight female university students were randomly assigned into 3 groups. INTERVENTIONS: two imagery techniques, one under relaxing and one under aggressive conditions were taught and then applied. In the control condition, discussions were conducted. MEASURES: traits such as goal orientation (task and ego), physical self-efficacy and self-control were measured prior to performing the task, while rate of perceived exertion task-specific determination (i.e., task-related confidence, commitment, exertion tolerance, and effort investment) were measured before, during and after the task. RESULTS: The results showed an average of 31% and 28% increase in exertion tolerance in participants who used aggressive and relaxation imagery techniques respectively, compared to 4% reduction in the controls. RM ANOVA indicated equality between the two imagery groups but both were significantly different from the control group. Physical self-efficacy, self-control, and task-specific determination were found nonsignificant, but their important roles in coping with aversive stimuli are highlighted. It was evident that the "coping" mechanism rather than the "distraction" mechanism accounted for the larger sustain in the "zone of exertion tolerance". CONCLUSIONS: Imagery can be used efficiently in exertion tolerance but more studies are needed on athletes.

Adolescent↗

PubMed1997

Perception-action relationships in strategic-type settings: covert and overt processes.

In this paper, we present a new approach to studying the perception-action linkage in sport. The approach and the sport-specific paradigms associated with it are aimed at exploring the 'covert' processes underlying decision-making and decision alterations before and during the course of action execution. The approach introduced here is based on Coles' (1989) work applying the chronometric approach in various paradigms using warning and imperative stimuli (i.e. valid and invalid cueing). Coles also demonstrated the efficacy of the 'lateralized readiness potential' as a measure which reflects the correct and incorrect activation of motor responses (i.e. the covert processes underlying error elicitation). The chronometric approach, which takes into account the warning and imperative stimuli as well as action initiation, execution and alteration, is recommended for the study of expertise behaviour in sport. It is predicted that lateralized readiness potential patterns will differ between experts and novice performers. Several hypotheses are derived, and paradigms suggested, to explore the 'covert processes' underlying expertise in the motor domain.

Arousal↗

PubMed1997

Effect of goal difficulty, goal specificity and duration of practice time intervals on muscular endurance performance.

The aims of this study were to explore the relationships between goal specificity, goal difficulty and performance, and to determine if setting unrealistic goals would produce decreases in performance. The subjects were high school students from 15 schools and an attempt was made to control for the effects of social comparison. The schools were randomly assigned to one of 15 conditions representing five levels of goal conditions-namely, 'do' (no goals), 'do your best', 'improve by 10%' (easy), 'improve by 20%' (difficult/ realistic) and 'improve by 40%' (improbable/unattainable)-and three levels of practice duration (4, 6 and 8 weeks). This design consisted of nesting goal difficulty within practice duration, which enabled an examination of the goal specificity and goal attainability/difficulty hypotheses proposed by Locke and Latham (1985). A 5 x 3 factorial ANCOVA was applied to the post-baseline sit-up gain scores. The results indicated that all specific groups performed better than all non-specific groups. In addition, across practice durations the difficult/realistic group exhibited the greatest increase in performance, followed by the easy group. The performance gains of the improbable/unattainable group were substantially less compared with the difficult/ realistic group after 4 and 6 weeks, but not after 8 weeks of practice. These results are in line with both the goal specificity and goal difficulty hypotheses derived from the application of Locke's goal-setting theory to sport.

Adolescent↗

PubMed1997

Aggression and violence in sport: an ISSP position stand.

Violent and aggressive behaviours have become common in a large variety of sport. The antecedents and consequences of such behaviours are outlined in the position statement issued by the International Society of Sport Psychology (ISSP). The ISSP recommends several actions be taken to minimize such acts in sport and encourages education of young athletes in line with fair-play ethics.

Aggression↗

PubMed1996

Crisis-related observations in competition: a case study in basketball.

This study presents a unique observational approach to basketball, based on the theory of psychological performance crisis in competition. The approach used takes into account the responses of a player' s actions to significant social factors such as team-mates, spectators, the coach and the referees. The contribution of this approach beyond traditional observational techniques is discussed. In our investigation, a single case design was used, in which a professional basketball player was observed during 10 home and 3 away games of the regular season. The relations between the observations and the crisis concept are discussed in detail. In addition, some relevant methodological and applied aspects are presented.

Adaptation, Psychological↗

PubMed1996

The effectiveness of resistance training in children. A meta-analysis.

Many recent studies have reported that resistance training can be effective in producing strength gains among prepubescents. These studies appear to refute the early claims of ineffectiveness of resistance training in children. A meta-analysis procedure combines the results of individual empirical studies and estimates a standardised effect, termed effect size. This effect size is based on the scores of the control and experimental groups before and after training. It defines the difference between the gain of the experimental and control groups, divided by the standard deviation of the pooled variances of both groups. A literature search revealed 28 studies which described a resistance training programme for girls and boys under the age of 12 and 13 years, respectively. Presumably, these children were pre- or early-pubescents. However, only 9 of these studies provided the necessary data to calculate the effect size and could be included in the analysis. The majority of the studies showed a gain in strength between 13 and 30%. The overall mean effect size was found to be 0.57. This signifies that following training, the average child in the resistance training group was above 71.6% of the children in the control group. The effectiveness of resistance training can be influenced by factors such as age and maturation, gender, as well as the frequency, duration and intensity of the training programme. The studies included in the analysis examined participants of varying ages and did not demonstrate a clear influence of age. Most studies examined only boys or a mixed group of boys and girls. Therefore, the influence of gender on the effectiveness of resistance training in prepubescents cannot yet be determined. Nevertheless, in the few studies where boys and girls were examined separately, no difference was found in the effect of resistance training between genders. It appears that a training frequency of twice per week is sufficient to induce strength gains in children. However, the minimal, or for that matter optimal, duration and intensity are not clear. Some of the weaknesses observed in the reviewed studies include: (i) the lack of control for a possible learning effect; (ii) non-randomisation into the training and control groups; (iii) no report of adherence rate; (iv) a reliance on boys as study participants; and (v) too little information on the type, volume and intensity of training. Future studies should take these weaknesses into consideration.

Age Factors↗

PubMed1996

Theoretical and practical considerations in investigating motivation and discomfort during prolonged exercise.

In this article a motivational perspective to exercise and sport are reviewed. The review emphasises the social-cognitive approach that has recently been utilised extensively in the sport psychology literature. The review concentrates on the goal perspective approach to achievement motivation, the concept of competitiveness in sport, and the psychological constructs of perceived competence, efficacy, and control in association with the environmental conditions under which performance is evaluated. An integrated model of motivation is postulated to better account for motor/physical performance. The model is used later to show how performance can be examined in emotionally (i.e., frustration) and physically (work hard) demanding situations that can be manipulated and standardised. Experimental Support for the model is provided.

Achievement↗

PubMed1995

Regulation of mental states and biofeedback techniques: effects on breathing pattern.

The purpose of the present study was to examine whether breathing pattern may be used as a reliable index for the effectiveness of techniques applied for the regulation of mental states. Heart rate (HR), breathing pattern, galvanic skin response (GSR), and electromyogram (EMG) of the frontalis muscle were measured in 39 male and female subjects aged 18-25 years during 10-minute treatment with relaxation technique (autogenic training and/or music) followed by 10 minutes of imagery training. In the first 7 sessions biofeedback (BFB) was not included, while during the last 6 sessions BFB was introduced and utilized by the subjects. Relaxation (music or autogenic training) led to a decrease in breathing frequency, attributed to lengthening of expiration time, as well as reduced HR, GSR, and frontalis EMG response. In most instances imagery training was related to an increase in these indices. Specifically, significant tachypnea was observed during imagery of sprint running. In most cases BFB substantially augmented the physiological responses. In conclusion, our data suggest that, compared with HR, GSR, and EMG responses, the breathing pattern is at least as sensitive to the mental techniques employed, and may be useful as a psychophysiological index for diagnosis and testing, especially in sport practice.

Adult↗

PubMed1995

The augmenting role of biofeedback: effects of autogenic, imagery and music training on physiological indices and athletic performance.

In this study, three psychoregulative procedures of relaxation and excitation were provided in combination with biofeedback to examine their role on physiological and athletic performance variables. Thirty-nine college students were randomly assigned to three groups of psychoregulatory treatment (autogenic and imagery training, AT+IT; music and imagery training, M+IT; autogenic, music and imagery training, AT+M+IT), one placebo group and the control group. Imagery was related to a 100-m run. The treatment and control conditions lasted 13 sessions of 20 min each. During the first seven sessions, the subjects in the treatment groups underwent 10 min of relaxation followed by 10 min of excitation. During the last six sessions, similar treatment was provided accompanied by frontalis EMG biofeedback. Heart rate, the galvanic skin response, EMG and breathing frequency (fb) were recorded three times during each session. In addition, an athletic task (100-m run) was examined at the outset, after seven sessions (no biofeedback) and after an additional six sessions (with biofeedback). Biofeedback was found to have a significant augmenting effect on physiological components and athletic performance when accompanied by autogenic, imagery and music training. Soft music was found to be as beneficial as other relaxation techniques. The results are compared with similar studies applying mental techniques with biofeedback, and new directions of investigation in the psychophysiological domain are suggested.

Adolescent↗

PubMed1994

Information recall of younger and older skilled athletes: the role of display complexity, attentional resources and visual exposure duration.

This study was concerned with the interactive role of experience of athletic skill with other relevant environmental variables (display complexity, attentional resources, exposure time of stimuli) on perception (recall) of structured handball game situations. Nineteen experienced (older) and 19 less experienced (younger) handball players were assigned randomly either to ball-bouncing (diverted attention) or to calm seated (focused attention) conditions. In each of the two conditions, the subjects were exposed to a total of 36 slides containing 2-3, 5-6 and 8-10 players. Eighteen slides were exposed for 0.5 s and 18 for 1.0 s. All the slides contained structured defence and offence situations. Recall scores were subjected to repeated-measures ANOVA using attention condition and age as between-subject factors and task complexity and exposure duration as within-subject factors. The results showed that the recall of less experienced players deteriorated more than the recall of more experienced players following exposure to complex displays (> or = 8 players) while engaging in a secondary task (bouncing). The findings suggest that research paradigms should be applied in the field of sport which share both ecological validity and a potential to discover the cognitive substrates underlying experience and age in skilled motor performance.

Adolescent↗