Validity and reliability of a linear positional transducer across commonly practised resistance training exercises

This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R² values of >0.85 for all variables excluding deadlift mean velocity (R² = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.     

Motivation for physical activity in young people: entity and incremental beliefs about athletic ability

Three studies are reported of children and youth aged 11–19 years (n?=?3478) examining the nature of beliefs about athletic ability. Drawing on related research in academic, moral and stereotyping domains, development of a psychometric instrument assessing athletic ability beliefs is detailed. Support was found for a multidimensional hierarchical structure that is invariant across age and gender. Confirmatory factor analysis revealed a structure comprising two higher-order factors of entity and incremental beliefs underpinned by beliefs that athletic ability is stable and a gift (entity), and is open to improvement and can be developed through learning (incremental). Incremental beliefs, indirectly through a task goal orientation, and entity beliefs directly, predicted self-reported amotivation towards physical education and sport. On the other hand, enjoyment of physical activity in youth was predicted directly by task orientation and incremental beliefs. Predictions concerning the moderating role of perceived competence were not supported. Our findings highlight the importance of ability beliefs and goals in understanding the determinants of physical activity in children and youth.     

Comparison of individual and group-based load-velocity profiling as a means to dictate training load over a 6-week strength and power intervention

ABSTRACT

This study compared the effects of dictating load using individual (ILVP) or group (GLVP) load-velocity profiles on lower-body strength and power. Nineteen trained males (23.6 ± 3.7 years) completed a back squat one-repetition maximum (1-RM), load-velocity profiling (LVP), and countermovement (CMJ), static-squat (SSJ) and standing-broad (SBJ) jump tests before and after 6 weeks of resistance training. Participants were randomly assigned to an ILVP, or GLVP intervention with intra-session load dictated through real-time velocity monitoring and prediction of current relative performance using either the participant’s LVP (ILVP) or a LVP based on all participant data (GLVP). Training resulted in significant increases in back squat 1-RM for the ILVP and GLVP group (p < 0.01; 9.7% and 7.2%, respectively), with no group-by-time interaction identified between training groups (p = 0.06). All jump performance significantly increased for the ILVP group (p < 0.01; CMJ: 6.6%; SSJ: 4.6%; SBJ: 6.7%), with only CMJ and SSJ improving for the GLVP group (p < 0.05; 4.3%). Despite no significant group-by-time interaction across all variables, the ILVP intervention induced a greater magnitude of adaptation when compared to a GLVP approach. Additionally, an individualised approach may lead to greater positive transfer to power-based movements, specifically vertical and horizontal jumps.     

A future at risk: children having children

Every day in the US, over 3000 teenagers become pregnant. The US adolescent pregnancy rate is higher than that in most other developed countries and is increasing. About half of the teenage pregnancies result in a live birth, and most of these mothers are unmarried and will not finish high school. The root cause of this problem is that the young women have a sense of worthlessness and hopelessness about their future that makes them establish the relationships that leave them with babies they are ill-equipped to rear. This is creating an ever-growing underclass condemned to poverty, to a dependency on welfare, and to continue the cycle. All of this results in an ever increasing burden on taxpayers. In Missouri, a bill was enacted in 1990 to address a number of school-related issues that are impacted by premature parenthood. Based on research, the bill makes schools responsible for the continued enrollment of pregnant teens. Alternative programs for pregnant and teen parents receive state aid through guidelines established by the Missouri Department of Elementary and Secondary Education which allow local school districts to design their own programs. Nationwide research indicated that the greatest need of the teenage parents is obtaining appropriate child care. Parenting education is also of vital importance as is appropriate prenatal care. These strategies, in addition to intervening in the lives of middle grade students to help them avoid premature parenthood, form the basis of a 5-step program developed by the Committee for Economic Development to address the problem of teen parenthood. In Missouri, emphasis has also been placed on involving teen mothers in the education of their children so that the children are ready for kindergarten. Despite the proven cost-effective nature of these programs for teen parents (which help avoid additional pregnancies), very few states have encouraged such programs, apparently because of the up-front costs. Until Americans decide to devote sufficient resources to this problem, it will continue to place the future of all of society at risk.     

Coping strategies and the influence of perceived parental support in junior national age swimmers

This study examines how national junior age group swimmers cope with poor performance and explores whether coping strategy use changes with perceptions of parental support. One hundred and four junior age group swimmers (mean age 14.2 years) completed a modified version of the COPE scale (Crocker & Issack, 1997) and the perceptions of Perceived Parental Support Scale (Van Yperen, 1995). Results showed that the swimmers in this sample used a mixture of behavioural and cognitive strategies with an emphasis upon individual or internally focused approaches. When analysing coping strategies and perceptions of parental support (high, medium and low), significant differences were found in the use of behavioural and cognitively orientated approaches. When perception of parental support was low, swimmers reported using less active and training-orientated mechanisms and a tendency to use strategies such as self-blame and venting of emotion. These findings suggest that the effectiveness and ability of coping strategies to adapt to differing situations may be contingent upon perceptions of perceived support for junior swimmers. This highlights an area for future research.