Development and validation of the Decision-Specific Reinvestment Scale

Abstract

Items from the Reinvestment Scale were modified to create a decision-specific version of the scale. Principal components analysis of responses from 165 participants revealed one-, two-, three-, and four-factor solutions for the Decision-Specific Reinvestment Scale. Confirmatory factor analysis of responses from a second sample of 111 participants revealed that a 13-item two-factor solution showed the best fit. The first factor comprised six items referring to conscious monitoring of the process involved in making a decision, and was termed decision reinvestment. The second factor, decision rumination, comprised seven items related to focus on negative evaluations of previous poor decisions. In an initial assessment of predictive validity, Decision-Specific Reinvestment Scale scores of 59 skilled team sport players were found to be highly correlated with coaches' ratings of players' tendency to choke under pressure (r = 0.74), with high Decision-Specific Reinvestment Scale scores indicating greater susceptibility to poor decision-making under pressure. It was concluded that the Decision-Specific Reinvestment Scale highlights a performer's predisposition to engage in behaviours detrimental to performance under pressure, namely decision reinvestment and decision rumination.     

The influence of variable resistance moment arm on knee extensor performance

Abstract

To enhance muscular strength, resistance training machines with a cam, incorporating a variable resistance moment arm, are widely used. However, little information is available about the influence of the variable resistance moment arm on torque, velocity, and power during muscle contraction. To address this, a knee extensor machine was equipped with a cam or with a semi-circular pulley that imposed a variable or a constant resistance moment arm, respectively. Fourteen physically active men performed two full knee extensions against loads of 40–80 kg in both conditions. Participants developed significantly higher torque with the pulley than with the cam (P < 0.001). The relative differences between pulley and cam conditions across all loads ranged from 8.72% to 19.87% (P < 0.001). Average knee extension velocity was significantly higher in the cam condition than in the pulley condition. No differences were observed in average and peak power, except at 50 and 55 kg. Torque–velocity and power–velocity relationships were modified when the resistance moment arm was changed. In conclusion, whatever the link, namely cam or pulley, the participants produced similar power at each load. However, the torque–velocity and power–velocity relationships were different in the cam and pulley conditions. The results further suggest that the influence of the machine's mechanism on muscular performance has to be known when prescribing resistance exercises.     

Energy turnover during 24 hours and 6 days of adventure racing

Abstract

Energy turnover was assessed in two conditions of mixed ultra-endurance exercise. In Study 1, energy expenditure and intake were measured in nine males in a laboratory over 24 h. In Study 2, energy expenditure was assessed in six males during an 800-km Adventure race (mean race time 152.5 h). Individual correlations between heart rate and oxygen uptake ([Vdot]O₂) were established during pre-tests when kayaking, cycling, and running. During exercise, energy expenditure was estimated from continuous heart rate recordings. Heart rate and [Vdot]O₂ were measured regularly during fixed cycling work rates to correct energy expenditure for drift in oxygen pulse. Mean energy expenditure was 18,050 ± 2,390 kcal (750 ± 100 kcal · h^?1) and 80,000 ± 18,000 kcal (500 ± 100 kcal · h^?1) in Study 1 and Study 2 respectively, which is higher than previously reported. Energy intake in Study 1 was 8,450 ± 1,160 kcal, resulting in an energy deficit of 9,590 ± 770 kcal. Body mass decreased in Study 1 (?2.3 ± 0.8 kg) but was unchanged in Study 2. Fat mass decreased in Study 2 (?2.3 ± 1.5 kg). In Study 1, muscle glycogen content decreased by only 60%. Adventure racing requires a high energy expenditure, with large inter-individual variation. A large energy deficit is caused by inadequate energy intake, possibly due to suppressed appetite and gastrointestinal problems. The oxygen pulse, comparing start to 12 h of exercise and beyond, increased by 10% and 5% in Study 1 and Study 2 respectively. Hence, estimations of energy expenditure from heart rate recordings should be corrected according to this drift.     

Differences in self-regulatory skills among talented athletes: The significance of competitive level and type of sport

Abstract

Research has shown that talented athletes outscore their mainstream peers on the basis of self-regulation. Although valuable, this does not tell us more about the distinction between good athletes and the best, which is a prerequisite in talent development. Therefore, we examined the self-regulatory skills of 222 male and female talented athletes aged 12–16 years as a function of competitive sport level (junior international or junior national athletes) and type of sport (individual or team sports). Multivariate analyses of covariance in combination with a discriminant function analysis revealed that “reflection” distinguishes between athletes at the highest levels of excellence. Furthermore, athletes playing individual sports had higher scores on “planning” and “effort” than team sport athletes, highlighting the importance of differences between types of sport. In conclusion, we emphasize the importance of reflection as a self-regulatory skill. Reflection facilitates the development of sport-specific characteristics, which may vary by type of sport. This means that an advanced sense of reflection may help talented athletes to acquire desirable characteristics during their “talent” years to ultimately reach adult elite levels of competition.     

Resting Electromyographic Triceps Surae Activity and Tonic Vibration Reflexes in Subjects with High and Average-Low Maximum Oxygen Uptake Capacities

This study was grounded in the belief systems and physical activity literature and investigated preservice teachers' belief systems toward curricular outcomes for physical education programs. Preservice teachers (N = 486; men = 62%, women = 38%) from 18 U.S. colleges/universities shared their beliefs about curricular outcomes. Preservice teachers completed a previously validated belief systems instrument designed to measure the relative importance of four outcome goals for programs (physical activity/fitness, self-actualization, motor skill development, and social development). Internal consistency reliability for the instrument was .98. A confirmatory factor analysis demonstrated a good fit of the current sample to the hypothesized outcomes model. Multivariate analysis of variance results revealed a significant interaction in outcome preservice teachers' priorities for year in school by region. The teachers' views also differed on the important outcome goals for physical education. Two critical “tensions” are discussed: (a) the need to examine more fully the consistency of preservice teacher/teacher belief systems, and (b) implications for teacher education and professional development programming. It is important to heed prospective teachers' voices and address their belief systems in teacher education programs.     

Resting Electromyographic Triceps Surae Activity and Tonic Vibration Reflexes in Subjects with High and Average-Low Maximum Oxygen Uptake Capacities

Abstract

This study was designed to investigate the effect of an interactive videodisc motor skill assessment training program on the development of preservice and inservice teachers' qualitative assessment proficiency on two motor skills: the overhand throw and catch. Twenty-seven preservice and 27 inservice physical education teachers were randomly assigned to one of three treatment conditions: interactive videodisc (IVD), teacher-directed (TD), or self-directed (SD). Motor skill qualitative assessment accuracy was evaluated on a pre- and post-test basis using a 50-item motor skill assessment accuracy test (10 performances rated on 5 components) for each skill. Analysis of covariance results indicated significant main effects for treatment for both skills. Post hoc tests revealed that for the over hand throw, the IVD and TD groups were superior to the SD group but not different from each other. For the catch, the IVD group was found to be superior to both the TD and SD groups. These findings are discussed in relation to the advantages of interactive videodisc in terms of efficiency and user independence and with comparable findings in other educational applications.     

Digit ratio (2D:4D) and performance in elite rugby players

Abstract

The relative length of the second and fourth digits (2D:4D) is a putative marker for prenatal testosterone. Low 2D:4D has been reported to correlate with high performance in sport in general. Here, for the first time, we examine the relationship between 2D:4D and performance in elite rugby players. The 44 players (28 forwards, 16 backs) were drawn from the Ospreys Rugby Union Club and 44 age-matched controls. The measures of performance comprised age-adjusted number of international performances (caps) for Wales, a comparison of coaches' first-choice League team with others, and the number of tries scored by backs in club matches. Compared with controls, players were larger and had lower 2D:4D for the right and left hand. With regard to number of caps, players with low 2D:4D in their right hand and low right 2D:4D compared with their left (right ? left 2D:4D difference) had high numbers of caps. First-choice players did not differ significantly from second-choice players in their 2D:4D but they did have a lower right ? left 2D:4D difference than second-choice players. Low right 2D:4D and low right ? left 2D:4D difference were significantly linked with large numbers of tries. We conclude that low right 2D:4D and low right ? left 2D:4D difference are predictors of high rugby performance.     

Hip adductor activations during run-to-cut manoeuvres in compression shorts: implications for return to sport after groin injury

Abstract

Athletes at high risk of groin strains in sports such as hockey and soccer often choose to wear shorts with directional compression to aid in prevention of or recovery from hip adductor strains. Large, eccentric contractions are known to result in or exacerbate strain injuries, but it is unknown if these shorts have a beneficial effect on hip adductor muscle activity. In this study, surface electromyography (EMG) of the adductor longus and ground reaction force (GRF) data were obtained simultaneously on 29 healthy individuals without previous history of serious injury while performing unanticipated 45° run-to-cut manoeuvres in a laboratory setting wearing shorts with non-directional compression (control, HeatGear, Under Armour, USA) or shorts with directional compression (directional, CoreShort PRO, Under Armour, USA), in random order. Average adductor activity in the stance leg was significantly lower in the directional condition than in the control condition during all parts of stance phase (all P < 0.042). From this preliminary analysis, wearing directional compression shorts appears to be associated with reduced stance limb hip adductor activity. Athletes seeking to reduce demand on the hip adductors as they approach full return to activities may benefit from the use of directional compression shorts.