The assessment of at-risk infants and toddlers with the Bayley Mental Scale and the Battelle Developmental Inventory: Beyond the data

The purpose of this study was to compare the usefulness of the Bayley Scales of Infant Development (BSID)-Mental Scales and the Battelle Developmental Inventory (BDI) in assessing the abilities of infants and toddlers from teen-parent families. The 34 children lived with their mothers, who ranged in age from 15 to 21. The results of the study indicate that these two developmental instruments cannot be used interchangeably and that one needs to look beyond the psychometric data in order to understand the results of infant and toddler assessment. The correlation between the BSID-Mental Development Index (MDI) and BDI Total score was −.03.     

The load-velocity profile differs more between men and women than between individuals with different strength levels

This study aimed to determine the suitability of the load-velocity relationship to prescribe the relative load (%1RM) in women, as well as to compare the load-velocity profile between sexes and participants with different strength levels. The load-velocity relationship of 14 men (1RM: 1.17 ± 0.19) and 14 women (1RM: 0.66 ± 0.13) were evaluated in the bench press exercise. The main findings revealed that: (I) the load-velocity relationship was always strong and linear (R² range: 0.987–0.993), (II) a steeper load-velocity profile was observed in men compared to women (Effect size [ES]: 1.09), with men showing higher velocities for light loads (ES: ? 0.81 and ? 0.40 for the y-intercept and 30%1RM, respectively), but women reporting higher velocities for the heavy loads (ES: 1.14 and 1.50 at 90%1RM and 100%1RM, respectively); and (III) while the slope of the load-velocity profile was moderately steeper for weak men compared to their strong counterpart (ES: 1.02), small differences were observed between strong and weak women (ES: ? 0.39). While these results support the use of the individual load-velocity relationship to prescribe the %1RM in the bench press exercise for women, they also highlight the large disparities in their load-velocity profile compared to men.     

Influence of upright versus time trial cycling position on determination of critical power and W′ in trained cyclists

Body position is known to alter power production and affect cycling performance. The aim of this study was to compare mechanical power output in two riding positions, and to calculate the effects on critical power (CP) and W′ estimates. Seven trained cyclists completed three peak power output efforts and three fixed-duration trial (3-, 5- and 12-min) riding with their hands on the brake lever hoods (BLH), or in a time trial position (TTP). A repeated-measures analysis of variance showed that mean power output during the 5-min trial was significantly different between BLH and TTP positions, resulting in a significantly lower estimate of CP, but not W′, for the TTP trial. In addition, TTP decreased the performance during each trial and increased the percentage difference between BLH and TTP with greater trial duration. There were no differences in pedal cadence or heart rate during the 3-min trial; however, TTP results for the 12-min trial showed a significant fall in pedal cadence and a significant rise in heart rate. The findings suggest that cycling position affects power output and influences consequent CP values. Therefore, cyclists and coaches should consider the cycling position used when calculating CP.     

False-performance feedback does not affect punching forces and pacing of elite boxers

Prior research indicates that providing participants with positive augmented feedback tends to enhance motor learning and performance, whereas the opposite occurs with negative feedback. However, the majority of studies were conducted with untrained participants performing unfamiliar motor tasks and so it remains unclear if elite athletes completing familiar tasks respond in a similar fashion. Thus, this study investigated the effects of three different versions of false-performance feedback on punching force (N), pacing (force over time) and ratings of perceived exertion (RPE) in 15 elite amateur male boxers. Athletes completed a simulated boxing bout consisting of three rounds with 84 maximal effort punches delivered to a punching integrator on four separate days. Day one was a familiarisation session in which no feedback was provided. In the following three days athletes randomly received false-positive, false-negative and false-neutral feedback on their punching performance between each round. No statistical or meaningful differences were observed in punching forces, pacing or RPE between conditions (P > 0.05; ≤ 2%). These null results could stem from the elite status of the athletes involved, the focus on performance rather than learning, or they may indicate that false feedback has a less potent effect on performance than previously thought.     

The effect of beetroot juice supplementation on repeat-sprint performance in hypoxia

This investigation assessed the effect of dietary nitrate (NO₃^?) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO_2peak 53.1 ± 8.7 mL.kg^?1.min^?1) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYP_BR; 13 mmol NO₃^?) or NO₃^–depleted BR placebo (HYP_PLA). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO₂) was measured during the warm-up. There were no significant differences observed between HYP_BR and HYP_PLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYP_BR compared with HYP_PLA. There was a moderate effect for VO₂ to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO₃^? may not improve repeat-sprint performance in hypoxia but may reduce VO₂ during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.     

The effects of attentional focus instructions on punching velocity and impact forces among trained combat athletes

Research indicates that instructing athlete’s to focus on bodily movements (internal focus of attention [IFA]) may hinder performance, whereas instructing them to focus on the movement outcome (external focus of attention [EFA]) often enhances performance. Despite the importance of instructions in striking combat sports, limited research has examined the influence of IFA and EFA on performance in well-trained combat athletes. This study investigated the effects of different instructional cues on punching velocity (m · s^?1) and normalised impact forces (N · kg^?1) among intermediate (n = 8) and expert (n = 7) competitive boxers and kickboxers. Athletes completed three rounds of 12 maximal effort punches delivered to a punching integrator on three separate days. Day one was a familiarisation session with only control instructions provided. In the following two days athletes randomly received IFA, EFA or control instructions prior to each of the three rounds. Athletes punching with EFA were 4% faster and 5% more forceful than IFA (P < 0.05), and 2% faster and 3% more forceful than control (P < 0.05). Furthermore, experts punched 11% faster and with 13% greater force compared with intermediate athletes (P < 0.05). EFA led to a positive effect on punching performance and should be favoured over IFA and control instructions.     

Ali–Frazier 1: Black Gladiators,White Promoters,and the Economics of Big-Time Boxing

Abstract

The March 1971 heavyweight championship bout between undefeated black boxers Muhammad Ali and Joe Frazier elicited numerous responses. Ali, because of his brash persona, refusal to be drafted into the Vietnam War, and outspoken criticisms of white racism, had become a potent symbol of 1960s rebellion and Black Power. Frazier, by claiming the heavyweight championship while Ali was banished, cozying up to white politicians, and refusing to criticize the US government, made himself a worthy foil for Ali’s politics. But as the rhetoric surrounding the fight intensified, regarding black masculinity, patriotism, and community pride, one key aspect of the fight opened up debates in a surprising realm: the economics of black athletes and the possibilities and limitations of black capitalism. In an era when black capitalist programmes emerged nationwide, and when African-American athletes took on more vocal roles as community activists, the battles over the bout’s financial promotion became intense. While the boxers took home an unprecedented $2.5 million each for their participation, total revenues reached nearly $30 million. Discussions of the fight’s payout shed light on a wide range of economic issues facing the black community, and some of the unresolved issues in the quest for civil rights.     

On the temporal and behavioural consistency of pre-performance routines: an intra-individual analysis of elite basketball players' free throw shooting accuracy

The effectiveness of pre-performance routines on skilled performance in a self-paced skill has yet to be verified. In this study, we examine the importance of temporal and behavioural consistency in these routines. The duration and specific pattern of behaviours exhibited before each free throw (n = 284) were observed during 14 National Basketball Association play-off games. An intra-individual standardized score was calculated for each shot's duration. Each player's dominant behavioural routine was identified and each shot was classified as "sequence followed" or "sequence not followed". No difference was observed in the success rates of shots associated with brief, long, and regular duration routines (P > 0.05). However, players were more successful when they followed their dominant behavioural sequence (83.77% success) than when they deviated from their specific behavioural pattern (71.43% success) (P < 0.05). The findings are interpreted in light of relevant theory and implications for practice are discussed.