Objectives The primary goal was to examine the influence of early specialization on the performance of senior elite swimmers. Secondly, to provide information about the influence of swim style, distance, sex, status, country, years of high-level competition (YHLC) and age in swimmer’s performance. Design Data was obtained from International Federation of Swimming (FINA) regarding the participants 2006–2017 of junior and senior World Championships (WCs). The final filtered database included 4076 swimmers after removing those participating only in junior WCs. Method Cramer V coefficient, double and triple-entry tables were used to measure the relationship between the positions occupied in junior and senior phases. A One-Way ANOVA analysis was used to explain the variables time and rank between swimmers who participated in junior and senior WC or just in senior in all the distances and swim styles (SS). A univariate general linear model (GLM) was used to examine the association between time/rank and category (swimmers that participated previously in junior WC or not); YHLC; country; status (highest finishing position: final/semi-final/heats) and age. Results Significant differences (p < .001) were found in the GLM, with Rank as dependent variable, for all the variables. Showing that swimmers that participated previously in junior categories obtained greater results in all the interactions, except in 1500m freestyle. Significant differences (p < .001) were found between the variables position and YHLC, showing the variable position improvements as swimmers attended more WCs. Conclusion Competing in junior WC has a positive influence in achieve posteriori success in FINA WC. YHLC have a positive impact to achieve better positions.

The manner in which an archer holds and releases the string of a recurve bow causes the arrow to flex during the bow’s power stroke and on its way from the bow to the target. While an experienced observer can subjectively evaluate an arrow’s pitch and yaw visually after it has left the bow, the arrow’s behaviour during the bow’s power stroke happens too quickly for visual observation. High-speed video is consequently a much more effective tool. Similarly, high-speed video is an effective tool for studying an archer’s technique during the bow’s power stroke. Mathematical models of the arrow’s behaviour in the horizontal plane during the bow’s power stroke have, to date, relied upon comparison of the arrow’s flexural shape with photographs. However, an implicit assumption of that process is that the archer’s technique is perfect. This paper provides an analysis of event times and the magnitudes of several key components of the arrow flex during the bow’s power stroke for sixteen world-class archers. Aside from being a powerful analysis tool in its own right, that data can also be used to evaluate mathematical models of arrow behaviour. It is concluded that archer technique variations could be a significant source of error where a single archer is used as a comparison for the mathematics, even if that single archer is amongst the world’s best.

The aims of the study were to (1) quantify the performance development of race times and key performance indicators of European swimmers across the last Olympic cycle (from 2016 to 2021) and (2) provide reference values for long-course swimming pool events for both sexes from 50 m to 1,500 m including butterfly, backstroke, breaststroke, freestyle, and individual medley. Individual events from the 2016 and 2021 European swimming championships were included. Specifically, 246 men (age: 24.2 ± 3.4 years, FINA points: 890 ± 40) and 256 women races (age: 24.2 ± 4, FINA points: 879 ± 38) of the finalists were recorded and key performance indicators and split times analyzed. Performance differences in finalists of the 2016 and 2021 European championships were determined by an independent t-test and Cohen's d effect size. Reference values were retrieved from 2021 European championship finalists and are provided for all key performance indicators. Race times improved significantly (P &lt; 0.05) or showed moderate (d = 0.5–1) to large effect sizes (d &gt; 1) in 14 (men) and 6 (women) out of 16 events. Improvements were primarily evident in 100 m and 200 m events for males, as well as BR and sprint events for female swimmers. While start times improved in 15 (men) and 14 (women) events, turn times remained inconclusive in both sexes. Generally, breakout distances increased. Clean swimming velocities were faster in 12 (men) and 5 (women) events. In particular, for alternating swimming strokes, i.e., backstroke and freestyle, effect sizes indicated improved swimming efficiency with an inverse relationship between reduced stroke rate and increased distance per stroke. Coaches and performance analysts may use the present reference values as comparative data for race analyses and to specifically prepare swimmers for the various race sections. Data on the performance development should be used to analyze swimmers' potential and set goals for the various events and the next Olympic cycle.

The start in swimming is a crucial phase of a race, where improvements in performance can be made. Twenty-four elite swimmers race pace starts were recorded from five above and below water 50 Hz video cameras. Body position at toe off was calculated from the recordings and consisted of the two-dimensional mass centre position at toe off, and the arm, trunk, front leg and rear leg angles. Horizontal, vertical and resultant velocity of the mass centre at toe off, time to 5 m, 10 m and 15 m were also determined. Whilst time to 5 m (starting performance) differed by 0.17 s between genders, body position at toe off showed no significant differences. The difference in start performance was mainly due to a difference in horizontal velocity at toe off. The relationship between arm angle and start performance warrants further investigation as there was a range of techniques adopted but no clear link to performance. The trunk angle at toe off was correlated to starting performance for both males and females. This study demonstrates that the body position at toe off is no different between genders but is a critical determinant of starting performance for both males and females.

Si~mnzary.-It was hypothesized that the speed and direction of movement are monitored by proprioceptive feedback and that extent is determined by integrating the rate signals in time (Gibbs, 1954). consideration of analogous servo mechanisms leads to the following predictions that were tested and confirmed ( p < 0.01) in tests using G female and 4 male Ss. Input data from vision or proprioception alone or from both senses will produce rapid, primary adjustments of equal accuracy. Terminal accuracy was measured to show that the end-points of most residual errors lie in a limited zone of cleat central vision, as required by hypotheses. Various previous estimates alleging gross inaccuracy of proprioceptors (Ludvigh, 1952;Crawford, 1960) are shown to be erroneous and irrelevant.Various hypotheses of the functions of proprioception and of the interaction of senses have been stated and tested in a previous study (Gibbs, 1954). T h e present paper describes further tests of major hypotheses, that the extent of rapid, aiming movements is determined by the use of integral-error control and that proprioception provides negative feedback. Servo-mechanisms provide appropriate models of the postulated processes. I n these systems, control is based upon comparison of the required and achieved states of conuolled members, these states are indicated by input and feedback signals, respectively. In organisms, vision frequently detects a target and thus defines system input, but proprioception may define the target and also provide feedback, as in bringing the forefingers together in darkness.By hypotheses, control processes based upon proprioceptive feedback set limits to the accuracy of rapid, primary adjustments. It follows that system accllracy will not be improved when the precision of input data exceeds that of output data. Unequivocal predictions from the hypotheses are that primary adjustments will be equally accurate when either vision or proprioception defines the target, and no advantage will be gained by combining cues from both modalities as compared w~t h using either alone. The accuracy of movements must deteriorate, however, when input data are less precise than output information. Proprioception and peripheral vision usually interact to define the initial error, i.e., the starting and end-points of large movements, and no advantage would be gained by defining one component of the error more precisely than the ocher. I t follows from hypotheses that peripheral vision and proprioception provide input data of comparable accuracy.I t is a truism, not an hypothesis, that variable errors of under-and over-shoot- Research Paper No. 509.