Comparing the validity and output of the GT1M and GT3X accelerometer in 5- to 9-year-old children

The purpose of this study was to compare the validity and output of the biaxial ActiGraph GT1M and the triaxial GT3X (ActiGraph, LLC, Pensacola, FL, USA)accelerometer in 5- to 9-year-old children. Thirty-two children wore the two monitors while their energy expenditure was measured with indirect calorimetry. They performed four locomotor and four play activities in an exercise laboratory and were further measured during 12 minutes of a sports lesson. Validity evidence in relation to indirect calorimetry was examined with linear regression equations applied to the laboratory data. During the sports lessons predicted energy expenditure according to the regression equations was compared to measured energy expenditure with the Wilcoxon-signed rank test and the Spearman correlation. To compare the output, agreement between counts of the two monitors during the laboratory activities was assessed with Bland-Altman plots. The evidence of validity was similar for both monitors. Agreement between the output of the two monitors was good for vertical counts (mean bias = −14 ± 22 counts) but not for horizontal counts (−17 ± 32 counts). The current results indicate that the two accelerometer models are able to estimate energy expenditure of a range of physical activities equally well in young children. However, they show output differences for movement in the horizontal direction.

Efficient team actions: Outline of a theory of teams in sport

So far, social psychology in sport has preliminary focused on team cohesion, and many studies and meta analyses tried to demonstrate a relation between cohesiveness of a team and it's performance. How a team really co-operates and how the individual actions are integrated towards a team action is a question that has received relatively little attention in research. This may, at least in part, be due to a lack of a theoretical framework for collective actions, a dearth that has only recently begun to challenge sport psychologists. In this presentation a framework for a comprehensive theory of teams in sport is outlined and its potential to integrate the following presentations is put up for discussion. Based on a model developed by von Cranach, Ochsenbein and Valach (1986), teams are information processing organisms, and team actions need to be investigated on two levels: the individual team member and the group as an entity. Elements to be considered are the task, the social structure, the information processing structure and the execution structure. Obviously, different task require different social structures, communication and co-ordination. From a cognitivist point of view, internal representations (or mental models) guide the behaviour mainly in situations requiring quick reactions and adaptations, were deliberate or contingency planning are difficult. In sport teams, the collective representation contains the elements of the team situation, that is team task and team members, and of the team processes, that is communication and co-operation. Different meta-perspectives may be distinguished and bear a potential to explain the actions of efficient teams. Cranach, M. von, Ochsenbein, G., & Valach, L. (1986).The group as a self-active system: Outline of a theory of group action. European Journal of Social Psychology, 16, 193-229.

Emotional contagion in team sports and its impact on individual performance – an experimental study

In sport psychology research about emotional contagion in sport teams has been scarce (Reicherts & Horn, 2008). Emotional contagion is a process leading to a specific emotional state in an individual caused by the perception of another individual’s emotional expression (Hatfield, Cacioppo & Rapson, 1994). Apitzsch (2009) described emotional contagion as one reason for collapsing sport teams. The present study examined the occurrence of emotional contagion in dyads during a basketball task and the impact of a socially induced emotional state on performance. An experiment with between-subjects design was conducted. Participants (N=81, ♀=38, M=21.33 years, SD=1.45) were randomly assigned to one of two experimental conditions, by joining a confederate to compose a same gender, ad hoc team. The team was instructed to perform a basketball task as quickly as possible. The between-factor of the experimental design was the confederate’s emotional expression (positive or negative valence). The within-factor was participants’ emotional state, measured pre- and post-experimentally using PANAS (Krohne, Egloff, Kohlmann & Tausch, 1996). The basketball task was video-taped and the number of frames participants needed to complete the task was used to determine the individual performance. The confederate’s emotional expression was appraised in a significantly different manner across both experimental conditions by participants and video raters (MC). Mixed between-within subjects ANOVAs were conducted to examine the impact of the two conditions on participants’ scores on the PANAS subscales across two time periods (pre- and post-experimental). No significant interaction effects but substantial main effects for time were found on both PANAS subscales. Both groups showed an increase in positive and a reduction in negative PANAS scores across these two time periods. Nevertheless, video raters assessment of the emotional states expressed by participants was significantly different between the positive (M=3.23, SD=0.45) and negative condition (M=2.39, SD=0.53; t=7.64, p<.001, eta squared=.43). An independent-samples t-test indicated no difference in performance between conditions. Furthermore, no significant correlation between the extent of positive or negative emotional contagion and the number of frames was observed. The basketball task lead to an improvement of the emotional state of participants, independently of the condition. Even though participants PANAS scores indicated a tendency to emotional contagion, it was not statistically significant. This could be explained by the low task duration of approximately three minutes. Moreover, the performance of participants was unaffected by the experimental condition or the extent of positive or negative emotional contagion. Apitzsch, E. (2009). A case study of a collapsing handball team. In S. Jern & J. Näslund (Eds.), Dynamics within and outside the lab. Proceedings from The 6th Nordic Conference on Group and Social Psychology, May 2008, Lund, pp. 35-52. Hatfield, E., Cacioppo, J. T. & Rapson, R. L. (1994). Emotional contagion. Cambridge: University Press. Krohne, H. W., Egloff, B., Kohlmann, C.-W. & Tausch, A. (1996). Untersuchungen mit einer deutschen Version der „Positive und Negative Affect Schedule“ (PANAS). Diagnostica, 42 (2), 139-156. Reicherts, M. & Horn, A. B. (2008). Emotionen im Sport. In W. Schlicht & B. Strauss (Eds.), Enzyklopädie der Psychologie. Grundlagen der Sportpsychologie (Bd. 1) (S. 563-633). Göttingen: Hogrefe.

Soziale Emotionsinduktion im Sport und deren Auswirkung auf die individuelle Leistung beim Lösen einer Gruppenaufgabe

In der Sportpsychologie gibt es bis anhin wenige Studien, welche sich mit dem Phänomen der sozialen Emotionsinduktion befassen (Reicherts & Horn, 2008). Die soziale Emotions-induktion ist ein Prozess, bei welchem der blosse emotionale Ausdruck einer Person ein emotionales Befinden bei einer anderen Person auslöst, welche diesen emotionalen Ausdruck wahrnimmt (McIntosh, Druckman & Zajonc, 1994). Von Apitzsch (2006) wird die soziale Emotionsinduktion in einem theoretischen Artikel als eine mögliche Ursache bezeichnet, warum es zu einem Kollaps von Teams im Sport kommen kann. Die vorliegende Arbeit untersucht die beiden Fragestellungen, ob es beim Lösen einer sportbezogenen Aufgabe unter Teammitgliedern überhaupt zu sozialer Emotionsinduktion kommt und welche Auswirkungen sich daraus für die individuelle Leistung der Teammitglieder ergeben. Zu diesem Zweck wur-den zwei experimentelle Studien mit unterschiedlicher Methodik durchgeführt: Im ersten Experiment mit Between-Subjects Design wurden die Versuchsperson (N = 81, ♀ = 38, M = 21.33 Jahre, SD = 1.45) zufällig einer der beiden experimentellen Bedingungen zugeordnet, wobei sie auf einen Konfidenten trafen, mit welchem sie ein gleichgeschlechtliches Ad Hoc Team bildeten. Als Team mussten sie eine Basketballaufgabe so schnell wie möglich lösen. Der Zwischensubjekt-Faktor des experimentellen Designs was der emotionale Ausdruck des Konfidenten mit positiver oder negativer Valenz und der Innersubjekt-Faktor, das emotionale Befinden der Versuchspersonen, welches prä- und postexperimentell mit der Positive and Negative Affect Schedule erfasst wurde (PANAS: Krohne, Egloff, Kohlmann & Tausch, 1996). Die Zweiergruppe wurde beim Lösen der Basketballaufgabe auf Video aufgenommen und die Anzahl der Frames, welche die Versuchspersonen zur Aufgabenlösung brauchten, wurde als individuelles Leistungsmass verwendet. Im zweiten Experiment wurden dem Konfidenten drei Versuchspersonen (N = 78, ♀ = 33, M = 20.88 Jahre, SD = 1.64) zugeordnet und als Gruppe durchliefen sie beide experimentellen Bedingungen, womit es sich also um ein Within-Subjects Design handelte. Das prä- und postexperimentelle Befinden der Versuchspersonen wurde mit dem Mehrdimensionalen Befindlichkeitsfragebogen erfasst (MDBF: Steyer, Schwenkmezger, Notz & Eid, 1997). Es zeigte sich in beiden Experimenten, dass das emotionale Befinden der Konfidenten von den Versuchspersonen sowie von Videoratern als unterschiedlich zwischen den Bedingungen wahrgenommen wurde (Manipulation-Check). Auch wenn sich eine Tendenz für eine soziale Emotionsinduktion teilweise zeigte, waren die durchgeführten, messwiederholten Varianzanalysen, welche die Auswirkungen der beiden experimentellen Bedingungen auf die Veränderung des emotionalen Befindens der Versuchspersonen prüfen sollten, nicht signifikant. Die durchgeführten t-Tests zeigten überdies, dass sich die Leistung der Versuchspersonen nicht zwischen den beiden experimentellen Bedingungen unterschied. Mit den beiden durchgeführten Experimenten konnten somit die Ergebnisse anderer experimenteller Studien zur sozialen Emotionsinduktion in Gruppen nicht repliziert werden (z.B. Barsade, 2002). Vor diesem Hintergrund wurden abschliessend methodische Änderungen diskutiert, welche eine Verbesserung der Vorgehensweise bei der Erfassung der sozialen Emotionsinduktion in Gruppen beim Lösen einer sportbezogenen Aufgabe zur Folge hätten.

The effect of aerobic exercise on intrahepatocellular and intramyocellular lipids in healthy subjects

BACKGROUND Intrahepatocellular (IHCL) and intramyocellular (IMCL) lipids are ectopic lipid stores. Aerobic exercise results in IMCL utilization in subjects over a broad range of exercise capacity. IMCL and IHCL have been related to impaired insulin action at the skeletal muscle and hepatic level, respectively. The acute effect of aerobic exercise on IHCL is unknown. Possible regulatory factors include exercise capacity, insulin sensitivity and fat availability subcutaneous and visceral fat mass). AIM To concomitantly investigate the effect of aerobic exercise on IHCL and IMCL in healthy subjects, using Magnetic Resonance spectroscopy. METHODS Normal weight, healthy subjects were included. Visit 1 consisted of a determination of VO2max on a treadmill. Visit 2 comprised the assessment of hepatic and peripheral insulin sensitivity by a two-step hyperinsulinaemic euglycaemic clamp. At Visit 3, subcutaneous and visceral fat mass were assessed by whole body MRI, IHCL and IMCL before and after a 2-hours aerobic exercise (50% of VO(2max)) using ¹H-MR-spectroscopy. RESULTS Eighteen volunteers (12M, 6F) were enrolled in the study (age, 37.6±3.2 years, mean±SEM; VO(2max), 53.4±2.9 mL/kg/min). Two hours aerobic exercise resulted in a significant decrease in IMCL (-22.6±3.3, % from baseline) and increase in IHCL (+34.9±7.6, % from baseline). There was no significant correlation between the exercise-induced changes in IMCL and IHCL and exercise capacity, subcutaneous and visceral fat mass and hepatic or peripheral insulin sensitivity. CONCLUSIONS IMCL and IHCL are flexible ectopic lipid stores that are acutely influenced by physical exercise, albeit in different directions. TRIAL REGISTRATION ClinicalTrial.gov NCT00491582.

The effect of a single 2 h bout of aerobic exercise on ectopic lipids in skeletal muscle, liver and the myocardium.

AIMS/HYPOTHESIS Ectopic lipids are fuel stores in non-adipose tissues (skeletal muscle [intramyocellular lipids; IMCL], liver [intrahepatocellular lipids; IHCL] and heart [intracardiomyocellular lipids; ICCL]). IMCL can be depleted by physical activity. Preliminary data suggest that aerobic exercise increases IHCL. Data on exercise-induced changes on ICCL is scarce. Increased IMCL and IHCL have been related to insulin resistance in skeletal muscles and liver, whereas this has not been documented in the heart. The aim of this study was to assess the acute effect of aerobic exercise on the flexibility of IMCL, IHCL and ICCL in insulin-sensitive participants in relation to fat availability, insulin sensitivity and exercise capacity. METHODS Healthy physically active men were included. [Formula: see text] was assessed by spiroergometry and insulin sensitivity was calculated using the HOMA index. Visceral and subcutaneous fat were separately quantified by MRI. Following a standardised dietary fat load over 3 days, IMCL, IHCL and ICCL were measured using MR spectroscopy before and after a 2 h exercise session at 50-60% of [Formula: see text]. Metabolites were measured during exercise. RESULTS Ten men (age 28.9 ± 6.4 years, mean ± SD; [Formula: see text] 56.3 ± 6.4 ml kg(-1) min(-1); BMI 22.75 ± 1.4 kg/m(2)) were recruited. A 2 h exercise session resulted in a significant decrease in IMCL (-17 ± 22%, p = 0.008) and ICCL (-17 ± 14%, p = 0.002) and increase in IHCL (42 ± 29%, p = 0.004). No significant correlations were found between the relative changes in ectopic lipids, fat availability, insulin sensitivity, exercise capacity or changes of metabolites during exercise. CONCLUSIONS/INTERPRETATION In this group, physical exercise decreased ICCL and IMCL but increased IHCL. Fat availability, insulin sensitivity, exercise capacity and metabolites during exercise are not the only factors affecting ectopic lipids during exercise.

The effects of exercise on self-rated sleep among adults with chronic sleep complaints

Purpose The purpose of this study was to evaluate whether and to what extent the observed effects on self-rated sleep in a previous study using a combined treatment program with physical exercise and sleep education can be attributed by the physical activity (PA) component. Methods The present study reports supplementary analysis of an already described and published study. Data were provided by a nonclinical sample of 98 normal-active adults with chronic initiating and the maintaining of sleep complaints. The additional analysis included sleep log, exercise log, and daily pedometer data which were collected during a baseline week and 6-week of a combined intervention. Results The results indicate that the number of steps (p = 0.02) and the duration of PA (p = 0.01) is significantly related to the improvement in subjective sleep measures and therefore reveal an independent effect within this combined sleep program. Sleep diary data (recuperation of sleep, number of awakenings after sleep onset, and wake time after sleep onset time) improved significant (all p < 0.01) over the intervention program. About 50% of the participants stated that the PA had an effect on their improvement. Conclusion Improvements on subjective sleep quality after a combined intervention cannot be attributed to the cognitive component alone, but PA has an independent effect. Adults with chronic sleep complaints benefit from exercise. Therefore structured PA should be implemented in any sleep management programs.

Beta-alanine supplementation improves jumping power and affects severe-intensity performance in professional alpine skiers.

INTRODUCTION Supplementation with beta-alanine may have positive effects on severe-intensity, intermittent, and isometric strength-endurance performance. These could be advantageous for competitive alpine skiers, whose races last 45 to 150 s, require metabolic power above the aerobic maximum, and involve isometric muscle work. Further, beta-alanine supplementation affects the muscle force-frequency relationship, which could influence explosiveness. We explored the effects of beta-alanine on explosive jump performance, severe exercise energy metabolism, and severe-intensity ski-like performance. METHODS Nine male elite alpine skiers consumed 4.8 g/d beta-alanine or placebo for 5 weeks in a double-blind fashion. Before and after, they performed countermovement jumps (CMJ), a 90-s cycling bout at 110% VO2max (CLT), and a maximal 90-s box jump test (BJ90). RESULTS Beta-alanine improved maximal (+7 ± 3%, d = 0.9) and mean CMJ power (+7 ± 2%, d = 0.7), tended to reduce oxygen deficit (-3 ± 8%, p = .06) and lactate accumulation (-12 ± 31%) and enhance aerobic energy contribution (+1.3 ± 2.9%, p = .07) in the CLT, and improved performance in the last third of BJ90 (+7 ± 4%, p = .02). These effects were not observed with placebo. CONCLUSIONS Beta-alanine supplementation improved explosive and repeated jump performance in elite alpine skiers. Enhanced muscle contractility could possibly explain improved explosive and repeated jump performance. Increased aerobic energy production could possibly help explain repeated jump performance as well.

Optimal lange Fixationen? Eine experimentelle Studie zu überlangen "QuietEye"-Dauern

Einleitung: Im Zusammenhang mit der Leistungsdienlichkeit langer finaler Fixation (quiet eye, QE) wird vermutet, dass Leistungsverbesserungen nur für eine optimale Dauer zu beobachten sein sollten, also auch bei „überlangen“ QE-Dauern die Leistung wieder abnimmt (u.a. Janelle et al., 2000; Klostermann, 2014). Jedoch liegen zu dieser Vermutung bislang keine empirischen Befunde vor, so dass in der hier präsentierten Studie Präzisionsleistung in einer Wurfaufgabe in Abhängigkeit von (auch) sehr langen experimentell kontrollierten QE-Dauern untersucht wurde. Methode: In einem Within-subject-Design hatten 20 Sportstudierende unter acht verschiedenen QE-Bedingungen (Onset in 400-ms-Schritten von -3200 ms bis -400 ms vor Bewegungsbeginn; 16 Versuche pro Bedingung in randomisierter Abfolge) mit retro-reflektierenden Bällen auf eine Großleinwand projizierte Zielscheiben möglichst mittig zu treffen. Die QE-Manipulation erfolgte über eine an den Bewegungsbeginn gebundene Zielscheibeneinblendung samt Wurfrhythmisierung durch Tonvorgaben. Aus den mit einem Vicon-T20-System (200 Hz) sowie einem integrierten mobilen Eyetracker (EyeSeeCam, 220 Hz) erhobenen Daten wurden die QE-Dauer (ms) und die Wurfleistung (radialer Fehler, mm) als abhängige Variablen berechnet und varianzanalytisch auf Unterschiede untersucht. Resultate und Diskussion: Für die QE-Dauer wurde ein signifikanter Haupteffekt gefunden, F(7, 133) = 38.4, p < .01, ηp2 = .67, mit zumindest tendenziellen (-2000 ms vs. -2400 ms, -2800 ms vs. -3200 ms), größtenteils aber signifikanten QE-Anstiegen gemäß der experimentellen Manipulation (alle ps < .01), obgleich die jeweils angezielten QE-Dauern nicht erreicht und zum Teil deutlich unterschritten wurden (tatsächliche relativ zur angezielten Dauer im Mittel 59.95 %). Für den radialen Fehler ergab sich ein signifikanter Haupteffekt, F(7, 133) = 8.5, p < .01, ηp2 = .31, welcher durch signifikant schlechtere Leistungen bei den Onsets -400 ms und -800 ms gegenüber allen anderen Onsets erklärt wird (alle ps < .05; ausgenommen -400 ms vs. -800 ms und -800 ms vs. -2400 ms). Somit wurde der „klassische“ QE-Effekt schlechterer Leistungen infolge kurzer QE-Dauern repliziert; die Vermutung einer Leistungsverschlechterung bei überlangen QE-Dauern konnte jedoch – zumindest unter den infolge der Manipulation tatsächlich erzielten Werten – nicht untermauert werden. Literatur: Klostermann, A. (2014). Finale Fixationen, sportmotorische Leistung und eine Inhibitionshypothese: Mechanismen des „Quiet Eye“, Sportwissenschaft, 44, 49-59. Janelle, C. M., Hillman, C. H., Apparies, R. J., Murray, N. P., Meili, L., Fallon, E. A. & Hatfield, B. D. (2000). Expertise differences in cortical activation and gaze behavior during rifle shooting. Journal of Sport & Exercise Psychology, 22, 167-182.

The effect of ego depletion on sprint start reaction time

In the current study, we consider that optimal sprint start performance requires the self-control of responses. Therefore, start performance should depend on athletes' self-control strength. We assumed that momentary depletion of self-control strength (ego depletion) would either speed up or slow down the initiation of a sprint start, where an initiation that was sped up would carry the increased risk of a false start. Applying a mixed between- (depletion vs. nondepletion) and within- (before vs. after manipulation of depletion) subjects design, we tested the start reaction times of 37 sport students. We found that participants' start reaction times decelerated after finishing a depleting task, whereas it remained constant in the nondepletion condition. These results indicate that sprint start performance can be impaired by unrelated preceding actions that lower momentary self-control strength. We discuss practical implications in terms of optimizing sprint starts and related overall sprint performance.

Does context matter? Analysing structural and individual factors of member commitment in sport clubs

This article addresses factors that infl uence member commitment in sport clubs. Based on the theory of social action and the economic behaviour theory, it focuses not only on individual characteristics of club members but also on the corresponding structural conditions of sport clubs. Accordingly, a multilevel framework is developed for explaining member commitment in sport clubs. Different multilevel models were estimated in order to analyse the infl uences of both the individual and corresponding context Level in a sample of n = 1,699 members of 42 Swiss and German sport clubs. The multilevel analysis permitted an adequate handling of hierarchically structured data. Results of These multilevel analyses indicated that the commitment of members is not just an outcome of individual characteristics such as strong identifi cation with their club, positively perceived (collective) solidarity, satisfaction with their sport club, or voluntary engagement. It is also determined by club-specific structural conditions: commitment proves to be more probable in rural sport clubs and clubs that explicitly support sociability. Furthermore, cross-level effects in relation to member commitment were also found between the context variable sociability and the individual variable identification.

How narcissistic self-construction sabotages their relationships: Accuracy and bias in partner perception

Trapped by their superordinate goal to maintain a grandiose self, narcissists navigate their relationships wishing to re-assure themselves of their specialness and superiority, using strategies bound to fail. Dyadic analyses of diary data (14 days, 83 couples) showed that narcissists focus on their partners’ shortcomings, becoming experts at detecting negative forms of support, while simultaneously minimizing their partner’s positive intentions. Partners of narcissists, in contrast, appear to have a positive bias in ongoing relationships and seem to compensate for some of the narcissists’ shortcomings. Narcissists’ focus on their own selfconstruction purposes also extends to their parenting roles. In a retrospective study, narcissistic mothers were found to demand superior performance, desiring to show-off their child, yet concurrently attributing their child’s success to themselves. They also exercise psychological control and role-reversal, requiring the child to cater to their needs, and to admire them, while simultaneously oblivious to their child’s needs and desires.

Detecting single-target changes in multiple object tracking: The case of peripheral vision.

In sports games, it is often necessary to perceive a large number of moving objects (e.g., the ball and players). In this context, the role of peripheral vision for processing motion information in the periphery is often discussed especially when motor responses are required. In an attempt to test the basal functionality of peripheral vision in those sports-games situations, a Multiple Object Tracking (MOT) task that requires to track a certain number of targets amidst distractors, was chosen. Participants’ primary task was to recall four targets (out of 10 rectangular stimuli) after six seconds of quasi-random motion. As a second task, a button had to be pressed if a target change occurred (Exp 1: stop vs. form change to a diamond for 0.5 s; Exp 2: stop vs. slowdown for 0.5 s). While eccentricities of changes (5-10° vs. 15-20°) were manipulated, decision accuracy (recall and button press correct), motor response time as well as saccadic reaction time were calculated as dependent variables. Results show that participants indeed used peripheral vision to detect changes, because either no or very late saccades to the changed target were executed in correct trials. Moreover, a saccade was more often executed when eccentricities were small. Response accuracies were higher and response times were lower in the stop conditions of both experiments while larger eccentricities led to higher response times in all conditions. Summing up, it could be shown that monitoring targets and detecting changes can be processed by peripheral vision only and that a monitoring strategy on the basis of peripheral vision may be the optimal one as saccades may be afflicted with certain costs. Further research is planned to address the question whether this functionality is also evident in sports tasks.