The Influence of Response Distortion in Assessing Self-Perceptions of Physical Ability and Attitude Toward Physical Activity     

Rod K. Dishman 《Research quarterly for exercise and sport》2013,84(2):286-298

Abstract

Response distortion is an acknowledged concomitant variable in psychometric research. Although the influence of response bias on the Estimation scale of the Physical Estimation and Attraction Scales (PEAS) has previously been considered for adolescent males, experimental evidence concerning the sensitivity of the adult versions of both the Attraction and Estimation scales to “faking” has not been provided. To determine this sensitivity, adult versions of the PEAS were administered to male and female undergraduates (N = 122). Subjects were randomly assigned to one of three groups and received either “fake bad,” “fake good,” or standard instructional sets. Results generally supported the view that the total score on each of the Attraction and Estimation scales is relatively insensitive to attempts to “fake good.” However, attempts to “fake bad” consistently resulted in a significant decrease (p < .01) in both Attraction and Estimation scores as compared to a standard control group. These findings suggest the need for a criterion to detect suspected “fake bad” Attraction and Estimation responses and possibly a “fake good” Attraction response. Statistical procedures for determining test bias indicated that specific PEAS items discriminated between the experimental and control groups, and these items were incorporated into embedded scales for the detection of a distorted PEAS response. Evidence for the predictive validity of these “fake bad” and “fake good” scales was provided.  相似文献   

Progression and variability of competitive performance of Olympic swimmers     

David B Pyne  Cassie B Trewin  William G Hopkins 《Journal of sports sciences》2013,31(7):613-620

Estimates of progression and variability of athletic performance in competitions are useful for researchers and practitioners interested in factors that affect performance. We used repeated-measures mixed modelling to analyse 676 official race times of 26 US and 25 Australian Olympic swimmers in the 12-month period leading up to the 2000 Olympic Games. Progression was expressed as percent changes in mean performance; variability was expressed as the coefficient of variation in performance of an individual swimmer between races. Within competitions, both nations showed similar improvements in mean time from heats through finals (overall 1.2%; 95% confidence limits 1.1 to 1.3%). Mean competition time also improved over 12 months by a similar amount in both nations (0.9%; 95% confidence limits 0.6 to 1.2%). The US swimmers showed a greater improvement between the finals (a difference of 0.5%; 95% confidence limits ?0.2 to 1.1%), which paralleled changes in the medal haul of the two nations. The coefficient of variation in performance time for a swimmer between races was 0.60% (95% confidence limits 0.56 to 0.65%) within a competition and 0.80% (95% confidence limits 0.73 to 0.86%) between competitions. Our results show that: (a) to stay in contention for a medal, an Olympic swimmer should improve his or her performance by ～1% within a competition and by ～1% within the year leading up to the Olympics; (b) an additional enhancement of ～0.4% (one-half the between-competition variability) would substantially increase the swimmer's chances of a medal.  相似文献   

Energy system contribution to 400-metre and 800-metre track running     

Rob Duffield  Brian Dawson  Carmel Goodman 《Journal of sports sciences》2013,31(3):299-307

As a wide range of values has been reported for the relative energetics of 400-m and 800-m track running events, this study aimed to quantify the respective aerobic and anaerobic energy contributions to these events during track running. Sixteen trained 400-m (11 males, 5 females) and 11 trained 800-m (9 males, 2 females) athletes participated in this study. The participants performed (on separate days) a laboratory graded exercsie test and multiple race time-trials. The relative energy system contribution was calculated by multiple methods based upon measures of race [Vdot]O₂, accumulated oxygen deficit (AOD), blood lactate and estimated phosphocreatine degradation (lactate/PCr). The aerobic/anaerobic energy system contribution (AOD method) to the 400-m event was calculated as 41/59% (male) and 45/55% (female). For the 800-m event, an increased aerobic involvement was noted with a 60/40% (male) and 70/30% (female) respective contribution. Significant (P <?0.05) negative correlations were noted between race performance and anaerobic energy system involvement (lactate/PCr) for the male 800-m and female 400-m events (r = ? 0.77 and ??0.87 respectively). These track running data compare well with previous estimates of the relative energy system contributions to the 400-m and 800-m events. Additionally, the relative importance and speed of interaction of the respective metabolic pathways has implications to training for these events.  相似文献   

Effects of physical activities that induce moderate external loading on bone metabolism in male athletes     

L Maïmoun  D Mariano-Goulart  I Couret  J Manetta  E Peruchon  JP Micallef 《Journal of sports sciences》2013,31(9):875-883

Sports characterized by little or moderate weight bearing or impact have a low osteogenic effect. However, the action of such sports on bone turnover remains unclear. The objective of this study was to determine the effect on bone remodelling of physical activities that induce moderate external loading on the skeleton. Thirty-eight male athletes aged 18–39 years (cyclists, n?=?11; swimmers, n?=?13; triathletes, n?=?14) and 10 age-matched sedentary controls aged 22–35 years participated in the study. The study combined measurement of bone mineral density by dual-energy X-ray absorptiometry and bone turnover assessment from specific biochemical markers: serum bone-specific alkaline phosphatase, osteocalcin, urinary type I collagen C-telopeptide and calcium. Compared with the controls and swimmers, adjusted bone mineral density was higher (P?<?0.05) in triathletes at the total proximal femur and lower limbs. No differences in bone mineral density were found between cyclists, swimmers and controls. Compared with controls, osteocalcin was higher (P?<?0.05) in triathletes and swimmers and urinary type I collagen C-telopeptide was higher in swimmers only. Serum bone-specific alkaline phosphatase was lower (P?<?0.05) in cyclists than in all other groups. In conclusion, an osteogenic effect was found only in triathletes, mainly at bone sites under high mechanical stress. Bone turnover differed in athletes compared with controls, suggesting that bone turnover may be sport-practice dependent. Despite some encouraging observations, it was not possible to show that changes in the bone remodelling process were sport-discipline dependent.  相似文献   

Activity profiles of the Australian female netball team players during international competition: Implications for training practice     

Aaron Fox  Michael Spittle  Leonie Otago  Natalie Saunders 《Journal of sports sciences》2013,31(14):1588-1595

Abstract

In elite sport, to remain competitive at the international level, it is critical to understand the game demands on players to ensure sport specific training programmes are designed for optimal athlete preparation and conditioning. In netball, recent research examining the activity patterns of players at the elite level is lacking, with only one study undertaken on this level of competition in the past 30 years. Therefore, the aim of this study was to provide coaches with up to date knowledge of player activity patterns as a basis for the design of optimal sport specific training programmes. The Australian female netball team were analysed using video footage of three international test matches. Player activity was categorised into five movement and eight game-based activities; and further classified as work or rest. Results suggest that differences in the current game exist when compared to the previous analysis. Positional differences were also found with regard to player activity confirming the need for an individualised component of training based on player position.  相似文献   

Assessing Sitting Across Contexts: Development of the Multicontext Sitting Time Questionnaire     

Geoffrey P. Whitfield  Harold W. Kohl III 《Research quarterly for exercise and sport》2013,84(3):323-328

Purpose: To describe the development and preliminary evaluation of the Multicontext Sitting Time Questionnaire (MSTQ). Method: During development of the MSTQ, contexts and domains of sitting behavior were utilized as recall cues to improve the accuracy of sitting assessment. The terms “workday” and “nonworkday” were used to disambiguate occupational and discretionary sitting. An expert panel evaluated content validity. Among 25 participants, test–retest reliability of the MSTQ items was assessed with intraclass correlation coefficients (ICCs). Convergent validity was assessed versus relative and absolute accelerometer-estimated sedentary time and activity log using Pearson (r) or Spearman (ρ) correlation coefficients where appropriate. Results: Pilot testing revealed Web-based MSTQ administration was rapid, scalable, and inexpensive. Most items in the MSTQ demonstrated acceptable reliability (ICCs>.70). Compared with accelerometer-estimated sedentary time relative to total wear time, the MSTQ exhibited a low correlation on workdays (r = .34) and a moderately high correlation on nonworkdays (r = .61). Conclusions: The systematic development of the MSTQ resulted in several improvements over previous tools and may serve as a model for purpose-driven questionnaire design. Additional validation is needed to conclusively determine the utility of the MSTQ.  相似文献   

Book Review     

F. Colloud  P. Bahuaud  N. Doriot  S. Champely  L. Chèze 《Journal of sports sciences》2013,31(5):479-480

Abstract

The mechanical responses (i.e. external contact forces and external power) of 25 elite rowers to a race-pace rowing protocol were investigated on the traditional fixed stretcher mechanism and the more recently introduced free-floating stretcher mechanism rowing ergometers. Using a Rowperfect rowing ergometer for both conditions, external contact forces at the handle, stretcher and sliding seat, as well as the displacements of the handle and stretcher, were recorded. The external power was calculated as the product of the force and velocity data from both the handle and stretcher. Significant differences (P < 0.05) between the two conditions for each mechanical parameter were observed. The fixed condition showed larger maximum values for forces and external power and average power throughout the rowing cycle. Moreover, rowing with the fixed mechanism generated higher inertial forces during the transition between the propulsion and recovery phases, especially at the catch of the cycle. The results suggest that: (i) muscular coordination may differ according to the stretcher mechanism used, which could have an impact on the physiological adaptations of muscles; and (ii) the free-floating mechanism may induce lower catch and maximum values for net joint forces and net joint moments that could decrease the risk of injury.  相似文献   

Altitude and endurance training     

Heikki Rusko  Heikki Tikkanen  Juha Peltonen 《Journal of sports sciences》2013,31(10):928-945

The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (<2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is >12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.  相似文献   

Feasibility of eyes open alpha power training for mental enhancement in elite gymnasts     

Marian K. J. Dekker  Berber R. Van den Berg  Ad J. M. Denissen  Margriet M. Sitskoorn 《Journal of sports sciences》2013,31(16):1550-1560

Abstract

This study focuses on a novel, easy to use and instruction-less method for mental training in athletes. Previous findings suggest that particular mental capacities are needed for achieving peak performance; including attentional control, focus, relaxation and positive affect. Electroencephalography (EEG) alpha brain activity has been associated with neural inhibition during processes of selective attention, for improving efficiency in information processing. Here we hypothesised that eyes open alpha power training by music teaches athletes to (1) learn to self-regulate their brain activity, and (2) learn to increase their baseline alpha power, herewith improving mental capacities such as focusing the allocation of attention. The study was double-blind and placebo-controlled. Twelve elite gymnasts were either given eyes open alpha power training or random beta power training (controls). Results indicate small improvements in sleep quality, mental and physical shape. In our first attempt at getting a grip on mental capacities in athletes, we think this novel training method can be promising. Because gymnastics is one of the most mentally demanding sports, we value even small benefits for the athlete and consider them indicative for future research.  相似文献   

Psychological resilience in sport performers: a review of stressors and protective factors     

Mustafa Sarkar  David Fletcher 《Journal of sports sciences》2013,31(15):1419-1434

Abstract

Psychological resilience is important in sport because athletes must utilise and optimise a range of mental qualities to withstand the pressures that they experience. In this article, we discuss psychological resilience in sport performers via a review of the stressors athletes encounter and the protective factors that help them withstand these demands. It is hoped that synthesising what is known in these areas will help researchers gain a deeper profundity of resilience in sport, and also provide a rigorous and robust foundation for the development of a sport-specific measure of resilience. With these points in mind, we divided the narrative into two main sections. In the first section, we review the different types of stressors encountered by sport performers under three main categories: competitive, organisational and personal. Based on our recent research examining psychological resilience in Olympics champions, in the second section we discuss the five main families of psychological factors (viz. positive personality, motivation, confidence, focus, perceived social support) that protect the best athletes from the potential negative effect of stressors. It is anticipated that this review will help sport psychology researchers examine the interplay between stressors and protective factors, which will, in turn, focus the analytical lens on the processes underlying psychological resilience in athletes.  相似文献