Reliability and validity of different methods of estimating the one-repetition maximum during the free-weight prone bench pull exercise

ABSTRACT

This study examined the reliability and validity of three methods of estimating the one-repetition maximum (1RM) during the free-weight prone bench pull exercise. Twenty-six men (22 rowers and four weightlifters) performed an incremental loading test until reaching their 1RM, followed by a set of repetitions-to-failure. Eighteen participants were re-tested to conduct the reliability analysis. The 1RM was estimated through the lifts-to-failure equations proposed by Lombardi and O’Connor, general load-velocity (L-V) relationships proposed by Sánchez-Medina and Loturco and the individual L-V relationships modelled using four (multiple-point method) or only two loads (two-point method). The direct method provided the highest reliability (coefficient of variation [CV] = 2.45% and intraclass correlation coefficient [ICC] = 0.97), followed by the Lombardi’s equation (CV = 3.44% and ICC = 0.94), and no meaningful differences were observed between the remaining methods (CV range = 4.95–6.89% and ICC range = 0.81–0.91). The lifts-to-failure equations overestimated the 1RM (3.43–4.08%), the general L-V relationship proposed by Sánchez-Medina underestimated the 1RM (?3.77%), and no significant differences were observed for the remaining prediction methods (?0.40–0.86%). The individual L-V relationship could be recommended as the most accurate method for predicting the 1RM during the free-weight prone bench pull exercise.     

Jump higher,run faster: effects of diversified sport participation on talent identification and selection in youth basketball

ABSTRACT

The aims of this study were to examine the medium-term effects of previous experiences during early stages of sport development on physical capacities of under-13 (U-13) talented basketball players and, to identify variables that discriminated under-14 (U-14) national team training camp selection. Anthropometrical and physical measurements were collected during a basketball training camp. Previous sport experiences (6–10 years), maturity offset, power outputs for jumping and sprinting were determined. A cluster analysis was used to allocate the subjects according to their different levels of sport experiences (more specialized vs. less specialized) to allow creating a dummy variable for the subsequent analysis of the physical variables. A stepwise discriminant analysis was computed to identify the construct that best classifies selected and non-selected players for U-14 national team training camp. The less specialized group outscored more specialized in all physical parameters, irrespectively of gender. The Abalakov Jump Peak Power and Predicted Adult Height (PAH) could successfully discriminate selected from non-selected players for U-14 national team training camp in boys and PAHin girls. The diversified and non-specific sport stimulus during early ages seem to be determinant to the acquisition and development of fundamental movement skills of talented basketball players.     

Measurement Errors in Modified Pull-Ups Testing

In a review of 46 meta-analyses of gender differences, overhand throwing had the largest gender difference favoring boys (ES > 3.0). Expectations for gender-specific performances may be less pronounced in female Australian Aborigines, because historical accounts state they threw for defense and hunting. Overhand throwing velocities and kinematics were recorded in 30 female and male Aboriginal Australian children 6-10 years old. Results indicated the Aboriginal girls and boys were more similar in horizontal ball velocities than U.S. girls and boys. Throwing kinematics between girls and boys were also more similar in Australian Aborigines than U.S. children. Aboriginal girls threw with greater velocities than U.S., German, Japanese, and Thai girls, while the boys were similar across cultures.     

Energy Cost of Rebound-Running

Using Sonstroem, Harlow, and Josephs' (1994) expanded version of the Exercise and Self-Esteem Model (EXSEM; Sonstroem &; Morgan, 1989), we explored how 9 older adults (6 women and 3 men, aged 65–72 years) involved in a resistance training program experienced and perceived changes in physical self-worth (i.e., improved strength, functional competency, physical condition, and body satisfaction). We conducted three in-depth interviews with each participant over the course of the program. In individual log books, participants recorded the weight lifted and the number of repetitions for each exercise. Our findings showed the course of changes in physical self-perceptions in these older adults and how actual individual changes in strength performance related to perceived changes in important psychological outcomes.     

New Media,Micromobilization, and Political Agenda Setting: Crossover Effects in Political Mobilization and Media Usage

In November 2007, Dutch secondary school students revolted against a requirement known as the “1040-hour norm.” New Web technologies, like instant messaging, YouTube, and social networking sites, played an important role in the mobilization effort. In this article, the authors argue that these technologies facilitate a shift toward micromobilization by individuals and small groups. In this “1040-hour norm” case study, the authors analyze how the course of the political agenda-setting process is being transformed through the interplay between processes of meso- and micromobilization, and through new micro-to-mass media crossover effects. When supported by micromedia, the effects of micromobilization can create strategic surprises for traditional intermediary organizations and policymakers.     

‘Strong mothers make strong children’: sports,eugenics and nationalism in Brazil at the beginning of the twentieth century

Based on post-structural feminist and gender studies, the present article analyses the importance given to the practice of physical education, sports and exercise as part of the national policy to strengthen the Caucasian-Brazilian population at the beginning of the twentieth century, emphasising the priority made of the White female body as the most important instrument in strengthening the so called ‘White race’. All the editions of the Revista Educação Physica, the first magazine published specifically for physical education and sport in Brazil, was the primary research source. Other books, manuals, reviews from scientific congresses and official publications from the Brazilian Government at the time were also examined. Via the technical analysis of the contents of the aforementioned publications, it was possible to conclude that the Brazilian nationalist discourse at the time sought what was called the ‘refinement of the White race’ by strengthening its women while, at the same time, systematically ignoring Black women.     

A review on the basketball jump shot

The ability to shoot an effective jump shot in the sport of basketball is critical to a player's success. In an attempt to better understand the aspects related to expert performance, researchers have investigated successful free throws and jump shots of various basketball players and identified movement variables that contribute to their success. The purpose of this study was to complete a systematic review of the scientific literature on the basketball free throw and jump shot for the purpose of revealing the critical components of shooting that coaches, teachers, and players should focus on when teaching, learning, practising, and performing a jump shot. The results of this review are presented in three sections: (a) variables that affect ball trajectory, (b) phases of the jump shot, and (c) additional variables that influence shooting.     

Is passive drag dependent on the interaction of kayak design and paddler weight in flat-water kayaking?

Abstract

Drag is one of the major factors that influences kayaking performance. To focus on the drag of the kayak’s hull shape and the paddlers’ weight per se, the passive drag (D_p) was measured on a flat-water sprint course for one paddler with added weights. D_p was measured by an electromechanical towing device using a load cell, at incremental and constant velocities from 2.78 to 5.56 m/s. Three kayaks of different sizes and shapes (Nelo® K1 Quattro-M, ML, and L) were used and the paddlers’ body weight was adjusted with weights so the total paddler weight in the kayak was 65, 75, and 85 kg. The mean D_p increased by the power function of D = kvⁿ (mean R² = .990; SD .006). The D_p went from 21.37?±?1.29 N at 2.78 m/s to 89.32?±?6.43 N at 5.56 m/s. For the two lighter weighted kayaks (65 and 75 kg), the lowest D_p was observed with different kayak sizes (M, ML, or L) depending on the target velocity. The manufacturers suggest that paddlers should select a kayak size according to their body weight to minimise drag; however, the results of this study suggest that target velocities, and thus competition distance should also be factored into kayak selection.     

Training priority: Positive suggestions

“Keep the sand low, Mike, so it doesn't accidentally get in someone's eyes. That would hurt. Yes, like that — you and Jonathan are building some very long roads. Would a little water help you pack them smoothly?” This teacher's tone of voice is accepting, and her words show understanding of the lifelong learning process.