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The aim of this study was to determine a predictive equation of 1 repetition maximum (1RM) from local muscular endurance. Different athletic male populations were assessed: racket/ball games players (n = 31 ), power lifters (n = 22), swimmers (n = 28), and rowers (n = 29). After the 1 RM assessment for the bench press, the maximum number of repetitions (MNR) relative to the 1RM (85%, 75%, 60%, 40%, and 20%) was tested. No significant differences in strength evolution from 20% to 100% of the 1 RM was found between power lifters and racket/ball games players and between swimmers and rowers. However, differences in the strength evolution appeared between these 2 mixed groups (p < 0.01), with differences appearing from 75% of 1RM to lesser relative strength (p < 0.05). Nonlinear equations fitted best with the actual data for the capacity to repeat lifts. The evolution of strength from 100% to 20% of 1RM was better described when the groups' specific equations were used as demonstrated by [r.sup.2], and residuals range between the predicted minus the measured 1RM. The strength endurance competences for high loads (100%-75%) were adequately modelled by the equation based on the total population. The accuracy of the 1RM prediction was better when a reduced number of lifts was performed. For untrained or novice subjects, the use of group-specific equations for the all evolutionary profile of strength allows a good estimate of 1RM and provides adequate numbers of lifts for all levels of strength, thus optimizing the training programs. KEY WORDS training adaptations, prediction equation, maximal strength

We examined the vertical jump performance of each leg among 10 right-footed female ballet dancers with 1 yr. of international professional experience (quadrilles: Opera ballerinas). Their mean age was 17.5 yr. (SD=0.3). The maximal height of the unilateral jump was recorded, and muscle mass was evaluated by biphotonic absorptiometry method. Muscle mass and maximal jump height were similar for the two legs. A strong inverse relation was found between the muscle mass of the right leg (67%) and maximal jump height (r = -.81, p

The article discusses research about the coordination changes of the overarm throwing skills of children. The study examined the discontinuities and changes of the development of the skill from childhood through adolescent ages. It is suggested that motor skill patterns and discontinuity are related to the variability of the development of motor skills.

The study investigated blood markers allowing discriminating physiological responses to on-water rowing races, notably regarding training volume of athletes and race duration. College (COL) and national (NAT) rowers performed a 1000- or 2000-m race. Capillary blood samples obtained before and post-race allowed an analysis of a wide range of serum parameters. COL rowers had a lower rowing experience and training volume than NAT. Races induced a higher lactate concentration increase in NAT compared to COL (10.45 ± 0.45 vs 13.05 ± 0.60; p < 0.001). Race distance (2000 vs. 1000 m) induced a higher increase in fatty acids (0.81 ± 0.31 vs +0.67 ± 0.41; p < 0.05) and triglycerides concentration in NAT (0.33 ± 0.07 vs 0.15 ± 0.09; p < 0.01), but remained comparable between NAT and COL for the 1000-m races. Amino acids concentrations increased in NAT (0.19 ± 0.03, p < 0.01), but urea concentration increased only for NAT rowers having performed the 2000-m race (0.72 ± 0.22, p < 0.05). Transferrin concentration decreased after the 2000-m race (-0.60 ± 0.25, p < 0.05), and concentration changes of haptoglobin differed between NAT2000 (tendency to be reduced) and COL (tendency to by enhanced) (p < 0.05). Our results confirmed that the training level in rowing is associated with higher glycolysis utilization during maximal 1000- and 2000-m exercise and no difference for similarly trained subjects at these two distances. Our study also demonstrated that a 2000-m race could initiate fatty and amino-acid metabolisms in highly trained subjects. Therefore, these changes in blood parameter responses to a characteristic rowing exercise highlighted the importance of monitoring the physiological effects of training in sporting conditions and according to individual characteristics. [ABSTRACT FROM AUTHOR]

We examined the vertical jump performance of each leg among 10 right-footed female ballet dancers with 1 yr. of international professional experience (quadrilles: Opera ballerinas). Their mean age was 17.5 yr. (SD=0.3). The maximal height of the unilateral jump was recorded, and muscle mass was evaluated by biphotonic absorptiometry method. Muscle mass and maximal jump height were similar for the two legs. A strong inverse relation was found between the muscle mass of the right leg (67%) and maximal jump height (r = -.81, p< .01) but not for the left leg. These results highlight a functional asymmetry and the effect of motor laterality in dance. [ABSTRACT FROM AUTHOR]

Abstract Background The strength of a society’s response to a public health emergency depends partly on meeting the needs of all segments of the population, especially those who are most vulnerable and subject to greatest adversity. Since the early stages of the H1N1 pandemic, public communication of H1N1 information has been recognized as a challenging issue. Public communication is considered a critical public health task to mitigating adverse population health outcomes before, during, and after public health emergencies. To investigate knowledge and knowledge gaps in the general population regarding the H1N1 pandemic, and to identify the social determinants associated with those gaps, we conducted a survey in March 2010 using a representative random sample of U.S. households. Methods Data were gathered from 1,569 respondents (66.3% response rate) and analyzed using ordered logistic regression to study the impact of socioeconomic factors and demographic characteristics on the individual’s knowledge concerning H1N1 infection and transmission. Results Results suggest that level of education and home ownership, reliable indicators of socioeconomic position (SEP), were associated with knowledge of H1N1. Level of education was found to be directly associated with level of knowledge about virus transmission [OR = 1.35, 95% C.I. 1.12-1.63]. Home ownership versus renting was also positively associated with knowledge on the signs and symptoms of H1N1 infection in particular [OR = 2.89, 95% C.I. 1.26-6.66]. Conclusions Policymakers and public health practitioners should take specific SEP factors into consideration when implementing educational and preventive interventions promoting the health and preparedness of the population, and when designing communication campaigns during a public health emergency.

Background: Effects comparison of resistance exercises may require equalizing the exercise-induced dose, this is currently done by using methods based on total weight lifted or on sets performed until failure. Dose equalization of resistance training sessions by these methods was analyzed in the present study., Methods: Twelve trained participants performed five bench-press sessions with a similar relative endpoint determined by the inability to complete a set of 50% of the maximum repetitions number (MNR). Sessions were performed at 50 or 85% of one-repetition maximum (1-RM) with sets until failure or sets prescribing 50% of MNR. The last session was performed with a reduced recovery pause to match the exercise density (total weight lifted/pause duration) of a previous session., Results: Sessions resulted in different total weight lifted (3158±1592 kg at 85% of 1-RM vs. 5330±1967 at 50%, P<0.001) and number of sets until failure (5.1±1.9 at 85% of 1-RM vs. 2.9±1.1 at 50%, P<0.001). Matching of sessions' density suppressed the differences in the number of sets performed (P=0.50)., Conclusions: Protocols' equalization based on the total weight lifted is likely to result in exercise volumes close to maximums when performed with heavy loads, whereas equalization based on sets to failure could induce a sets number close to the maximum when performed with light loads. Current methods for protocols equalization rely on gross values of exercise volume without considering maximums, that can result in markedly unbalanced efforts and biased results. Prescribing each exercise volume according to its maximum might optimize the training protocols' equalization.